I absolutely agree with this. Especially with buttons that toggle state, you need to be careful to use the right terminology. But I think we can say “Mute on” and be understood: TVs would often display text like “Mute on” while silencing the volume and the status would disappear when the mute button was pressed again. Likewise, adjusting the volume should turn off mute, and doing so would hide the “Mute on” text. It bothers me when a website tells me a video’s sound is off or “click the tiny mute button to unmute and listen to this,” I’d often instead prefer that the video start playing without sound to get my attention but then stop and wait for me to interact with it. And if I interact, just throw up a countdown timer that says “Video starting (with audio) in 10 seconds…” and toss in a cancel button. Alternatively, forget the unmute toggle and show a giant volume slider. Let me drag the volume to the level I want it to be at and I won’t be surprised if it’s suddenly unmuted and too loud. We really need to work on these conventions a bit more…