Nobody wants to hear you coughing your phlegm-filled lungs out and eating the world's crunchiest chips in front of a jet engine turbine while your spouse yells at you in the background and a tiny angry dog yips at a baby that's crying its head off because your mechanical keyboard sounds like gunshots that the sirens outside are responding to.
The game defaults to open mic and many people will skip that first screen to get into the game. If people have to mute you, whatever you might have to say will be completely lost. So please, unless you have an accessibility reason for using open mic, use push to talk. I promise, it won't kill you. Then everyone, including you, can enjoy voice chat and leave it on and not have to mute anyone :)