Singular “they” is older than singular “you.” And note, of course, that the pronoun “you” is conjugated as a plural, and we deal with it just fine.

Because some more microseconds later, it’s the difference between being able to serve 1k requests per second and dropping connections, vs. 100k requests per second and working smoothly.

Doesn’t this assume that the bottleneck is that particular function? If the service as a whole chokes on something else at 500 requests per second, then making that particular function capable of handling 100k requests isn’t going to make a difference. For web apps, the bottleneck is often some kind of storage I/O or the limits of the network infrastructure.