I agree in general, but I’d say the quick greeting form of “how are you?” is a bit more than just “hello”. It also asks for confirmation that there is no immediate problem that warrants attention.

If you say “how you doing?” to a coworker in passing, yes it’s weird if they launch into a lengthy report about some malaise in their life, or how they are feeling about something sad they read in the news - that’s not what you were asking. But if they say “A bit stressed actually - our servers just went down!” then that’s not weird at all. So a quick “how are you” really means something like “(a) hi, and (b) no major problems?”.