Unfortunately Duckbar can't give mute button back. We need to submit Feature Requests to get good old features back.
Dropping mute icon, in my opinion, makes no sense. Yes, interface looks cleaner without mute icon but clips and clip information are not art - they're set of tools to let us edit audio!
All the time I must double-check if clip is muted by pressing mute button twice. If it gets a little bit brighter, it was muted. Now I realize that this has become a natural habit to me(!). Sick.