A couple of reasons for me. I want to sit and relax by playing a game. I don’t find being in voice chat with others relaxing. I don’t say much in general and basically feel like I’m needing to ‘perform’. I don’t like it so I choose not to do it. I have a health condition that can require me to stop whatever I’m doing with very little warning and it may be 30min+ before I can return. Not exactly conducive to playing with others. I understand and accept that this precludes me from a number of activities and means there are things I can’t obtain.