Well the SI unit for request rate is … requests/s. Just like speed is m/s and not something bespoke.
However when the infra is crumbling under requests (one could say decaying), then becquerel seems appropriate
And what if something goes from rest to light speed every second to average 1 m/s over the second. Is that the same thing as smooth 1 m/s?
For it to be an SI unit, shouldn't you be able to express it in terms of the 7 SI base units?