It's a minor inconvenience at the grocery store.
It's a major inconvenience to wear one at gyms.
It's a major inconvenience with regards to socializing with friends (a core human need), I really hate not being able to read other people's facial expressions when I talk to them.
It's a major inconvenience to require it at schools. It's horrible for kids not to be able to see the facial expressions of their teachers or classmates (especially when learning how to read and pronounce words!).