Almost every UI framework out there is single-threaded and has facilities to help offloading such tasks into the background. Usually, to a worker thread pool. It's a bit fiddly, especially in a non-managed language that doesn't protect from dumb mistakes, but it can be easily done.

io_uring is for use cases where the context switch overhead of system calls starts to matter. While async I/O can be justified for U/I programming, it's safe to say that a file manager won't ever benefit from io_uring.