Vercel is a hyper for-profit and closed platform, is that blocking innovation on Next.JS as an "open-source" framework?
Then again when they introduced their new Image component for the longest time it would by default use Vercel's paid image optimisation services, eventually it could be disabled but only with some weird and poorly/confusingly documented custom configuration entry.
There are more instances of similar such questionable actions by the NextJS maintainers. I'd rather have seen them just be open about what drove them to do these things.
The services Vercel offers have to do with deployment mainly. That's never going to be something a back end or front end framework will help you with directly.
App hosting and deployment has always been a secondary concern. Choice of database, caching, queuing service, etc has also always been a secondary concern apart from a backend/frontend framework.