As mentioned previously (many times), the idea of masks is to prevent you from spreading the virus to others, in the event that you are presymptomatic or asymptomatic.

It's an unselfish act, an inconvenience, to help prevent the spread of covid, and if everybody does it, then it should be fairly effective.

However, in today's society the concept of inconveniencing yourself for the benefit of others seems to be somewhat unpopular. Unfortunately.