I think I kind of feel tired of ts/js ecosystem. I think it comes down to these things.
constant change of library
The package library move fast. Next.js/React does not ship with auth, ui library and so on. The developer choose whatever package they want to install and create feature based on it. cool. However, the new package constantly appear like ohh this is new ORM and auth library. This is new schema validation library!! I started to feal like finally hitting point where decision fatigue. Lots of energy was spend to glue those tool together instead of building something. However, this also appreciate me of js/ts ecosystem that promotes idea of bring things as you need. not sure about Next.js since they offer lots of things included from start, but just vite with some framework offers minimum config and up to the developer that brings other things. Maybe somewhat closer to ideology of unix system(will get hated putting unix and js in same category)!
Skill stays in framework, not so transferable to other battery included framework or different field of programming.
React, especially Next.js seems very certain type of meta programming. When I started to learn React, I had hard time to grasp what is hook and weird style of programming. Lots of abstraction for routing, server side rendering and such. I do like next.js developer experience. Its feels like magic. However, if something goes wrong, someone have to look at those things and better to know the behind how magic is build. Vite, on the other hand, provide minimum good starting point to bring whatever you want and have less meta programming.
To be honest lots of llm tool or model appear everyday and i feel like i am missing out,but what I learned from js/ts ecosystem is that as much as you care those shinny trend tech, it is important to have fundamental of something that is not move anyway. Could be how web rendering works under the hood? how http, tcp, cookie, auth are build and learn that without use of framework?