It does provide protection to the wearer, if everyone does it. If all the people around them are wearing them and one of those people is infected, the wearer is

It does provide protection to the wearer, if everyone does it. If all the people around them are wearing them and one of those people is infected, the wearer is less likely to catch it. Trying to fit it into a altruistic or selfish category is a false dichotomy. The same for obeying stay at home orders. Just because a benefit is indirect (herd immunity benefit of universal vaccination, reducing r0 in a population from behavioral changes) doesn't mean it's not a benefit.