I think the worst volume control is on Mac OS Big Sur... the missing Volume Icon In Menu Bar. A second close is the volume controls on the MacBook Pro touch bar. Fairly subpar (push-and-hold).
And the Touch Bar volume controls are probably the nicest UX on a Touch Bar, since it allows to change the volume quite fast with a simple drag & slide.
My only gripe is that my 16” MBP gets so hot using the touch bar burns my finger.
It's nice that you can. But as clear affordances go, that really isn't one.