Mandatory Volunteering at Work

Why do we have to have mandatory volunteering in our workplaces? My supervisor has said multiple times it can be anything: for our church, kids, etc. That doesn’t change the fact that I don’t want to. I’m exhausted and barely getting from day to day as many of us are. What if you don’t go to church or have kids? I don’t have either. I just want to come to work and do my job and not worry about something extra that has nothing to do with my work affecting my performance review.