It’s the Kryptonians who retain the human’s knowledge/memories, not the other way around. So it
looks to many - on both sides even but
especially the Kryptonians - like an upgrade. Even though obviously we know it’s not. It
is possession, but really that’s what it was on
Buffy, too. But from the POV of the ones doing the possessing, it’s an upgrade, just like it was to the vampires when they turned people. The only difference here is that if somehow someone on
Buffy was returned to their original self (which was extremely rare in that ‘verse), they would also retain the memories of what the demon did in their stead (hence Angel’s years of agony over Angelus’ crimes). Here, those who went back to being their old human selves are the ones who “blacked out,” and the Kryptonians ain’t concerned about them, lol. But that’s also a mercy compared to the
Buffy version, as they at least don’t have to live with the memories of what they did while the Kryptonian was at the wheel.
I’ve watched first couple eps more times than I can count, and I never got the impression that the “history” with Morgan Edge was anything other than him being a well-known wealthy public figure that Lois was trying to expose as corrupt through her journalism when he bought the Daily Planet. There was no hint yet of the type of nefarious background that would have called for Superman intervening.
As for the other stuff, I think at this point it’s best if we just agree to thoroughly disagree, as I really don’t wanna get into all my issues with the current state of the MCU and why I’d take this over any of their shows thus far, lol.