But eventually music is just what sounds good

This. Theory isn’t and shouldn’t be a prescriptivist set of rules. For everything we say sounds bad you can typically find some context where it can be interesting or pleasant somewhere else

. I meanif you bang a diminished fifth it sounds pretty nasty, (unless that’s what you’re going for, really accounting for taste opens up a whole other bag of subjective worms tbh) but it can sound great in a flat V minor 7th chord.

People that get prescriptivist on theory are just trying to make an interesting personality around having “superior” knowledge instead of just enjoying music. It’s tool to understand music more deeply, that’s it