> io_uring doesn't replace poll/epoll, it effectively replaces typical event loop frameworks.

I'm sorry but that statement is incorrect. The same functionality is accomplished by either io_uring or epoll.

> every line in an application that calls read/recv needs to be refactored

If the GP finds it easy to refactor from poll to epoll they will find it no different to refactor from poll to io_uring; the only caveat being they won't exceed epoll's performance with the io_uring until the standalone syscalls are further refactored. They don't need to be. The statement is incorrect.