Yes, it can still have significant benefits. Async IO is an attempt to get around the performance issues and, given lots of kernel support that largely does not

Yes, it can still have significant benefits. Async IO is an attempt to get around the performance issues and, given lots of kernel support that largely does not exist today, it can bridge the gap to a degree, but it's never going to match just avoiding the entire issue. You can use things like XDP to get a lot of performance back but 0 context switches/ 0 copies is always going to be faster.