I don't know what I'd do if my iPhone didn't have physical volume buttons. When I watch videos on YouTube now, as soon as an ad starts playing, I just mute it by using the volume button and look away for a few seconds as I can't stand ads (sadly there isn't a dedicated mute button).
Nice, I need to come up with a solution for this on desktop. My dream is a Chrome extension which recognizes Youtube ads and auto-mutes while they are playing.
I have a single-button shell alias that calls it with appropriate options, and a slightly longer one that adds a dynamic range compression filter which is sometimes handy.