io_uring is significantly faster for certain workloads, but you can't expect that merely running a syscall via io_uring will somehow magically make it faster.

Replacing single sycalls with their equivalents in io_uring is generally slower than just making the syscall directly. io_uring still uses syscalls after all.

io_uring generally only wins if you can amortize its overhead across multiple simultaneous operations. Implementing readahead would be such a case, except you can accomplish the same amortization with a single preadv instead, which again turns into a single syscall for multiple reads.