The basic premise of Next is good, but it definitely has more overhead that in should, has odd "middleware", and is very hard to optimize. I view this mostly as a React problem though since any page requires full hydration and ships everything to the client. RSCs are... not my favorite for sure.

I too have been very frustrated by this, and I made an "Astro for dynamic sites" TypeScript framework called Hyperspan ( https://www.hyperspan.dev ) that aims to fill the gap in the JS ecosystem for a modern fully dynamic option that, similar to Astro, makes dynamic islands easy. I have enjoyed using it in all my own projects. Check it out if you want.