What worries me are the partner agreements Vercel is making with several enterprise products, making Next.js the only official frontend stack for their products.
With everything else being DIY integration, and lesser tooling.
I think for me the saving grace is the pervasiveness of the React paradigm. Porting code from React to Preact (obvs), Vue3, Stencil or Solid is easy peasy because the patterns are the same. And thanks god for that.
EDIT: Honestly a web components framework with 1-to-1 likeness in API would be first class. I'd jump immediately.
With everything else being DIY integration, and lesser tooling.