our state doesn't require them, but there are a lot of businesses around here that require masks - costco is definitely one of them. hospitals, doc offices, some of the grocery stores, and the airlines (tho they are providing them). we get a "briefing" 3 times a week, and at the one on wednesday, one guy said "we respect your decision to not wear a mask, but would prefer that you do".
honestly, they won't prevent COVID unless you're using the N95. if COVID's gonna get you, then COVID's gonna get you, regardless. I think it just makes people feel better about the whole thing, and, it's easier to wear one than have to wonder/look up who's requiring them and who's not. plus, it's allergy season here, and it hit Nicky hard, so we wear them every time we go out. he can't make it through a store without coughing and/or sneezing and/or snuffling, though we've made cracks about him not wearing one and seeing how fast we can clear out the store LOL!