> (...) where doing some useless work is better than doing no work (...)

This take expresses a fundamental misunderstanding of the whole problem domain. There is a workload comprised of hundreds of processes, some of which multithreaded, that need to be processed. That does not change nor go away. You have absolutely no suggestion that any of those hundreds of processes is "useless". What you will certainly have are processes that will be waiting for IO, but waiting for a request to return a response is not useless.