Right! If you want it to denote an action, you need to include the verb: "TURN ON" would be entirely clear. It's even clear if you sometimes DO want to show state / not a button "IS ON" is also perfectly clear. There's only a few that might he confused when the verb is shown, like "INCREASE," although I would have to work a little to imagine the UI where it's not clear whether the button is showing the verb or noun.
One of my big beefs with modern UI is two-state controls where it's impossible to determine what the current state actually is. Like a button that says "Music Off" where it's unclear if that means the music is CURRENTLY off, or if clicking the button turns it off.
you can get the same issue with icons too. The one that gives me anxiety is the microphone with a line through on a button. I _am_ muted or I should click to _mute_. If my kids are arguing in the background and it's an important call it can feel like a high stakes thing to get wrong and often times it only becomes clear what state I'm in by toggling a few times. Does the icon change to a mic without a line when I click or does the previously shown mic with a line now get coloured in, what does _that_ mean?