Of course no one has a more mature implementation of it than Next. The Next.js team designed it themselves!

It is hilarious to me that the industry has reinvented serving HTML to clients, but with many intermediate steps, and this is heralded as groundbreaking.

I still just prefer having a more clear separation of concerns with API routes instead of using server components. I want my frameworks to be way less fancy than what Next is pushing out these days. I get the feeling we're dealing with the consequences of Vercel employees needing to justify their promotions.