This makes no sense. Epoll is already non-blocking, you never waste time waiting for I/O as long as there is work to do. Io_uring only boosts CPU efficiency (batching of syscalls, for example), it does not reduce blocking.

Your right, I was imprecise with my wording. You waste time doing context switches + mapping/unmapping CPU buffers meaning for a given unit of time you can churn through more I/O meaning your user space CPU time goes up and system time goes down.