It came off as very Revenge of the Sith, where they had all these things that had to happen to fit it with the original trilogy, but they'd pissed away two and a half movies, so they just mindwiped the droids (or in this case Lex).
It was a framing device. The reading of the comic book is a way of saying that none of it really happened. The whole series was just stories in a comic book. The episode started with the woman sitting on a bad with her child and reading the book, then segues into the 'story' which was what we all saw, then it ends when she closes the book.
Yes, that was Chloe doing the reading, but consider that she could have just been a random woman reading her son a comic book.
Fellas, the most incredible thing about the Smallville comic book framing device is that it established that in 2018, a DC comic book issue is still just $2.99.
After sitting through 218 episodes (and suffering through more than a few), this was a decent ending to the series. Like everyone, there are some things I would have changed, but it was fine.
The highlight for me was Lex's two appearances. His scene with Clark made me wish that Rosenbaum never left. Everything else was done to tie up the loose ends - I think Clark spent a combined ten seconds defeating Doomsday (S8) and Apokolips after stressing about each for an entire season.
Then again, if I were to start nitpicking, I'd be sitting here for a month typing.
For me, the show was fun escapist entertainment on a Thursday or Friday evening. I will miss it, but I can't imagine that I would rewatch any of it again.