It is in character though, it's not like it came out of nowhere even if it was the wrong move. She's still learning how to navigate real relationships, after all.
That's what happened though... except it's less she's bitter and more of it's the only way she can have him for the short time she does get to. She chooses to complete the loop.
I don't want multiple endings, but I do wish they could've spread out the main romance to explore other romances, like cat girl and trap boy having a will they won't they romance where they both realize they'd actually just prefer to be friends, the dimedol growing closer to a rando with the...
Seems like the only explanation, they were gonna do a slow buildup to him gaining power through using the goddess and whatnot, but then blam he has always had more power cause infinite reincarnations.
Every time they willy nilly mention major time skips, like the 7 years, I think back to those encountered along the way. Like those at the port that he helped out, or how old the kids already would be. Or even how old his half elf kid must be at this point. Time waits for no one, and it really...
All they need to finish this story off is having a bonus final chapter where Asahina finally comes back, tries to find him and runs into everyone grown up in the attempt, find out he's already dead(from crime or whatever, his path wasn't a good one), and she leaves a bento on his grave for him.