I have my phone muted for most of the day, but I still want to be able to take pictures and use siri. It doesn’t even mute the speakers, only notifications. It sounds like you want to replace a switch that many people want to use, with one that few would.
I also have it muted most of the day; usually all day. Which effectively makes it useless as it is. Perhaps this puts me in the biased position of feeling it may be used for another purpose.
