I know Vercel has their fingers in a bunch of pies, but is there any significant vendor locking? I worked at a place where we just put nextJS in a docker container and hosted it ourselves, but maybe we would have got more on Vercel?
It's designed to be deployed on Vercel. Production-ready hosting part of the Framework is not Open Source nor well documented.
https://github.com/vercel/next.js/discussions/59167 https://www.netlify.com/blog/how-we-run-nextjs/
the official recommendation we got was to just run it on vercel
I would go as far to say that nextjs is not self-hostable in its current state if you expect high traffic and low latency.