I've also noticed the fragmentation of the ecosystem. There is still some powerful stuff out there, but it is hard to find and UX has a lot of room for improvement (especially for laypeople).

Part of the fragmentation (on the extension side at least) came from Manifest V3 which required a massive re-write of logic and introduced a lot of friction for userscript managers. Many projects just died or stayed in maintenance mode since it was a big undertaking. MV3 certainly has been a pain to work with on our side.