Am I misunderstanding how often IORING POLL is used?

Question

I am watching a video that says after a million operations its faster to use io_uring_poll. I haven't used io_uring much so I may be remembering things wrong but io_uring poll means use io_uring_enter with the IORING_SETUP_SQPOLL flag? I understand sometimes traffic drops but wouldn't most of the time the code be using atomics to check if there's more items in the completion queue? Wouldnt enter/poll be needed the rare second when traffic drops? Or is it called constantly? I never had to do that many operations so I don't know