I don't think they should have switched sides but make their own thing all together, grey jedi style. Maybe not even as allies but at least something new. Kylo was clearly never as into the whole "dark side" stuff the same way Vader was and Rey had barely any association to the jedi, except for being force sensitive.

Would this have been better? Maybe, but at least it would have been DIFFERENT from just rehashing the OT. I'd rather see something I like try and fail that to not try at all.