I don't think your memory is off, but I would offer some nuances. You may think I'm contradicting you at first, but once you get to the end of this, you'll find that I agree with you.
Speaking strictly in terms of the writing: the SMALLVILLE version of Clark Kent's character didn't hold together very coherently. The most glaring fault in the way Clark was written throughout the series was actually summed up by you when you remarked, "Throughout Season 8, Clark is trying so hard to save Davis Bloom from his fate as Doomsday. If Clark had tried as hard to save Lex as he tried to save Davis, I don't think Lex would have gone evil."
For most of Seasons 1 - 7, Clark's confidence in human nature seems nearly non-existent. Even when he loses his powers, he maintains The Secret towards Lex; he joins a football team of bullies and psychopaths; he has no dedicated ambition to use his power to save people and never seems to go on patrol -- there is something very lacksidasical and callous about how someone with Clark's powers self-isolates on a farm for most of Season 7. The only thing he seems to care about is Lana.
Season 8 rebooted Clark's character significantly to who he probably should have been by Season 2: he is actively pursuing his goals of serving the world as a superpowered first responder, he is going on patrol, he is building a network of allies and support staff, and Lana is in his past.. However, this drastic improvement also created some oddities in character-continuity.
In Seasons 1- 7 Clark having killed any number of supervillains by throwing them into sharp objects or turning their powers on them or heat visioning them or electrocuting them in the heat of combat. Season 8 abruptly has Clark not only declare that he doesn't kill, but acts like that's always been the case, particularly when Clark judges Oliver Queen as morally bankrupt for (supposedly) blowing up Lex Luthor with Luthor's own bomb, to the point of kicking Oliver off the Justice League (only for everyone on the League to take Oliver's side once Clark isn't looking).
The result is that Clark looks like a hypocrite even though, paradoxically, this was probably the first time the writers had really tried to stay true to the comic book character. It's very strange: the show consistently insists that Clark believes in the decency of all human beings and has a high moral standard, but in actuality, Clark is distant and aloof and guarded and didn't practice in Seasons 1 - 7 what he preaches in Season 8.
Henry Cavill's character seems to have all of the flaws described above: Clark kills in the heat of combat and if angry, he might well do it again. He fights with rage and fury when his mother or Lois are threatened and is otherwise tightly wound and coiled up. As a child, Clark saved a schoolbus full of children and was told by his father that perhaps he should have let them all drown.
Clark's father was later caught in a tornado and commanded Clark to stand by and do nothing to save him lest his powers be exposed to the public; Clark complied. These experiences have left Clark doubtful and shaken, untrusting and suspicious of others. His father didn't trust the world to treat Clark well or to see his powers used for good.
When Clark throws a punch against a superpowered alien invader, it devastates small town buildings, shatters skyscrapers. In MAN OF STEEL, Clark is undoubtedly surrounded by 200,000 dead people in the wreckage of the fight with Zod when he flirts with Lois and kisses her, implying a certain disconnection from human experience.
We could assume that, in MAN OF STEEL, Clark spent weeks after the Kryptonian attack digging out bodies and survivors and rebuilding the city just as he was trying to find survivors of the Capitol in the ULTIMATE EDITION of BATMAN VS. SUPERMAN... but we never see it and it's never discussed.
And, as with SMALLVILLE, this version of Clark was drastically rebooted into a distinctly altered personality. The depiction of Clark in JUSTICE LEAGUE under Joss Whedon's direction and writing is noticeably very different: Clark in JUSTICE LEAGUE is indulgent, happy to let some little boys interview him for their podcast, and answering all their questions with thought and sincerity.
He describes kindly how the S-insignia is not an S, but a river, that winds and flows, representing the flow of hope. When asked what his favourite thing is about Earth, Clark genuinely ponders the question and smiles brightly as he answers.
Later, Clark bursts into the battle against Steppenwolf, but just as quickly flees when he hears the cries of civilians in danger and turns his attention to them first, engaging in a friendly competition with the Flash to see who can save more people.
Ultimately, the writing of Tom Welling's Clark and Henry Cavill's Clark, at least to me -- have a lot of the same problems. Both depictions suffer from a distinct lack of proactive compassion and empathy whether it's for guest-stars, extras and potential collateral damage, or their local communities. They are focused on juvenile soap opera crap (Lana or Lois) instead of saving lives.
Both versions of Clark display little to no trust in human nature, hide from their problems and struggles, are motivated by a fixation on a woman, and are passive until they are reactive. However, Welling's Clark is a defensive fighter who seeks to contain and immobilize while Cavill's Clark seems to fight with decades of pent-up frustration and fury.
But -- that's the *writing*. The memories that Slider_Quinn21 has shared of Tom Welling and Henry Cavill seem to be less about the writing and rather the impression that these two actors left on Slider_Quinn21's mind. And in terms of the performances, these two actors could not be more different.
Henry Cavill is a very aloof, guarded actor who, when playing troubled characters (like Clark in a Zack Snyder movie), holds his characters at a distance from their actions and their supporting casts. Cavill's characters are burying their secrets, insecurities, demons and fears away from the world while still bearing the weight of them. Cavill adopts a distant and somber presence for this.
The result is that Cavill's Clark can seem really joyless -- except when Cavill is performing a Joss Whedon script where he has to save civilians and tell jokes, and suddenly, Cavill's aloofness is replaced by a glowingly warm, commanding charisma.
Tom Welling, however, is not aloof or guarded. Tom a paradox: he is an introvert who wears his heart on his sleeve. Tom is a low-key, quiet soul who likes to buy out the stock of children's toy stores and spend weekends in his garage putting them in gift wrap so that he can distribute them to low income families come Christmas. Tom's inherent thoughtfulness, compassion and decency of character is not a performance, but a genuine expression of his true self.
As a result, Tom Welling's screen presence exudes a superhuman level of patience, goodwill, trust, caring, kindness and belief in the fundamental decency and positive potential of all human beings. There is a delicate caring to Tom's onscreen persona that the camera picks up: the carefulness with which he walks and speaks to others, the humility with which he listens, the patience that he conveys, that makes Tom seem superhumanly kind even when the writing isn't on his side.
MAN OF STEEL and BATMAN VS. SUPERMAN 'suffered' from excessive budgets where Superman's powers are most memorably rendered in Superman punching supervillains, smashing them through walls and buildings and cities. The most memorable images of Henry Cavill's Clark are him flying and punching as buildings (presumably filled with people) are reduced to rubble. This does not create the impression of a great humanitarian.
Despiet Joss Whedon's efforts, Henry Cavill's Superman will be remembered as a cold, distant, troubled Superman of war.
SMALLVILLE had the 'advantage' of a low budget at a time when digital effects were very costly. As a result, SMALLVILLE was limited to only showing Clark's powers in one specific area: the supersave. While Clark was not very proactive in Seasons 1 - 7, he did use his powers at least once an episode, and Clark's feats were always in rescuing people: shielding passengers from their exploding cars, ripping innocent people out of the path of bullets, pulling people out of crashing trains, catching girders before they pulped a human being, yanking people away from fires, catching people as they fell, etc..
As a result, the most memorable images of Clark across 10 seasons is Clark rescuing someone whether it's his parents or or Lex or Chloe or Pete or Lana or some random guest star of the week. Saving people is what Clark did most frequently onscreen in SMALLVILLE. Saving people is where SMALLVILLE put the bulk of the budget. As a result, the common memory people have of SMALLVILLE's Clark is that he is a compassionate protector and rescuer, and the fact that he was a little lax and uncommitted to the job before Season 8 is easily forgotten.
And ultimately, while the first seven seasons of writing let SMALLVILLE down, I think Tom Welling and the special effects artists put in the work to ensure that SMALLVILLE's Clark will always be remembered and loved as for their vision of Clark Kent as a superhuman paramedic, firefighter, first responder and as a character of empathy and compassion.
Ultimately, I think both Welling and Cavill suffered from writing that didn't suit them or their roles, but Welling spent more time saving people and had a more naturally compassionate screen presence (because that's what he's like in real life), so he seems much nicer than Cavill.
It would feel a lot easier to ask Tom Welling's Clark to do your podcast than to ask Henry Cavill's... although Henry Cavill's Clark will do your podcast too, which demonstrates how if the writing is there, the actor can incorporate it into the character.