There a variety of reasons why you may want to mute yourself that aren’t for antisocial reasons. You may be in a household with alot of background noise, someone may have approached in real life and wishes to speak to you, and certain conditions or illnesses could cause you to make very unpleasant noises you don’t wish the mic to pick up.
I understand however, that it may not be possible to implement a dedicated push to talk button due to the lack of available buttons on some controllers.
On the Vive for example, most of the buttons are already used, and the only one that could feasibly be changed to become a PTT key is the menu button since it can be opened via a gesture, but then that causes problems for people who preferred to use the button and opens a whole new can of worms. You may say that could be easily resolved by implementing controller remapping, and while appreciated, this would likely take some effort to implement that would be better spent continuing to improve other areas of the game, so that’s probably not an option either.
Therefore the best way input I would see being available is a gesture/pointing, but this would not be feasible for many disciplines due to needing both hands during combat. In this case, it would be better to make it so that performing this gesture would mute or unmute yourself.
Although this is already possible in the menu it would be less clunky for people that like to switch back and forth. Being able to quickly just point at your mouth or ear instead of putting your weapon away and navigate through multiple menus would be a major QOL improvement.