The origin of the terms have nothing to do with it, and they historically apply to a broad range of races and peoples, but I guarantee when the average person hears "master/slave" their first thought is likely "American south" and not "IDE Drive configuration" or "hydraulic system", so unless I've misinterpreted you by mistake, I'm not sure how you could seriously claim "the terms master and slave have nothing to do with [the historical systemic dehumanization of PoC]"
I understand it's more syllables to say "primary/secondary", but you can also use:
- Active/Standby
- Parent/Child
- Main/Secondary
- Initiator/Target
- and far more
Changing our habits is annoying and takes effort, but I dont know why people are so enthusiastic to hang onto a term that refers to a historically dehumanizing relationship that people are still unwillingly subjected to in the modern day.