Sound Settings menu malfunctions

This appears to be a hardware-independent issue. So on the Sound Settings menu, Output tab, there is a bar at the top with a mute button next to it. Due to its position at the top of the window, one might imagine that this is the master volume control which multiplies its own volume by the volumes of each of its constituent sources before outputting the final sound. But it's not. Instead, it's the volume of the highlighted output channel in the "Play sound through" column of sound sources.

But nevermind the counterintuitive design. The real problem is that you cannot get a given sound source to play unless you highlight it with the orange selector bar. It doesn't matter whether you've unmuted it on the bar at the top of the window. (Logically, that would be the master mute, but it's not because Sound Settings remembers whether or not each individual channel is muted.)

And worse, this not-really-master-output-volume bar still appears even when I'm selecting an input source, making it look like the mute for the input source is at the top of the window, when in fact it's to the right of the input source. (So what would that mute on top even do in that case -- mute the channel that I randomly happened to leave selected in the output source menu?)

I've never seen a sound control interface where not highlighting the name of the sound source before you close the window causes it to become muted. FYI I'm using a USB headset attached to a laptop with speakers, and a monitor with speakers connected over HDMI. I don't think further hardware details are relevant here, but I can provide them if need be.

Enough said. This GUI needs an overhaul.