We needed this episode, imo. Not for the twists/backstory, but for Lana. She was the one character that wasn't quite clicking with me, but this episode changed that, so in that sense, I feel like it did its job. Her fangirling over Superman was adorable even if it is a little crazy that she didn't even remotely recognize Clark or think he looked familiar.
As for the rest, I feel like I need to withhold judgment on the Kryptonian mythos and big picture until we see how it plays out. Because there's still some fishy stuff going on here that I suspect may not be as it seems at present. The Eradicator is more than what they showed here, and I still suspect it will turn out to be before the end (maybe have some sort of sentience at least). Just as I suspect there's more to "Morgan Edge"'s (because I have no clue how to spell his Kryptonian name) grand plan, considering how nonplussed he was about his failure here. I also don't trust who he claims to be, considering Lara didn't seem to confirm it. A part of me suspects that he is a creation of Zeta Rho, and not a biological son, and that the Eradicator will live through him. Or something. IDK. But there's definitely more to it than what we learned here, imo. And I think there's a reason they made a point to illustrate that the Eradicator isn't a computer, it's a brain. That brain's gonna end up in a host, I'd bet money.
I've got no issue with Lara having created this tech, because she was basically trying to create something humans would love to be able to achieve themselves - a way to preserve their consciousness beyond death. There was a Black Mirror episode (or two) about that, lol. It wasn't some nefarious thing. That Zeta Rho guy (interesting name, considering Zeta and Rho were two separate characters from the Bronze Age) is the one who turned it into the Eradicator. It's also kind of a fun nod to Superman Lives, where Jor-El created it (and it was as similar type of device there, I believe). And of course in 90's comics it was Kal-El's ancestor that created it, so it's not too far a deviation, imo.