MacOS has the ability to prioritize audio threads to avoid scheduling misses [0]. Linux has a set of patches [1] to give it soft real-time capabilities. I don't know as much about Windows, but I assume it has similar capabilities.

And it's not like this is ABS firmware, where someone might die if you miss your deadline, and where hard real-time OSes are used. But you do get glitches in the audio stream, which in performance contexts is still pretty bad.

[0] https://developer.apple.com/documentation/audiotoolbox/workg... [1] https://wiki.archlinux.org/index.php/Professional_audio#Real...