N-95 masks work to keep you from catching the virus and cloth or paper masks (somewhat) prevented you from spreading the virus. Ideally everyone would have worn N-95 masks but the US had four problems:

1) The US didn’t have enough N-95 masks. In Asia where masks in public were more common people used masks from their home supply. I think some segments of the population were resentful that the US didn’t have access to the best masks and Asia did. 2) We had only a general idea of who was high risk. 3) We had only a general idea of the long term impacts of the virus. There was some initial concern that the virus could be like the Zitka virus where mortality rates dramatically increase with the second exposure. If that were the case the second waves could have killed off half the population with wide transmission. 4) Households aren’t homogeneous and it is near impossible to prevent transmission from a possibly asymptomatic child to a high risk adult when they share the same home.

Unfortunately given the lack of consistent messaging about masks in the US one segment of the populations believed that the masks were to protect themselves and the other segment believed it was to protect others. Those that were low risk and believed it was to protect themselves resented the masks and those that saw the masks as a way to protect others resented those that resented the masks. I think those polarized views still persist today.

5) A not insignificant part of the population heard and understood that masks protect others and said "why should I suffer to protect them?"

I observed this sentiment in particular about return to school, and not just about masks. A sizable portion of the population would seemingly do anything to avoid accidentally helping someone else.

Yeah 5) was a real eye opener for me. A lot of conservative thought revolves around the idea that government shouldn't provide services that family, faith, and friends can provide, but when it came right down to it voluntary mask wearing was out because of exactly what you said.

Related: I wasn't in the US at the time, but I think a close 6) would have to be the intense polarization and ongoing "culture war," wherein one side was already being told that something else coming out of their mouth was literally killing people, and doubting the veracity of the statement. Wearing a mask is slightly panic-inducing anyway (ever try to muzzle a dog?), and coupled with the fact that one side of the political isle took up its championing, this allowed some members of one side to wear the mask sanctimoniously and some members of the other to avoid or disbelieve any rhetoric (scientific or otherwise) promoting their use. As long as the more general lack of cooperation carries on, the US is at risk of not being able to unify over important things like public health.

Paper masks (and, by some measure, even gaiters) are for source control, and they work just fine for that purpose if the literature is anything to go by. Every software project needs it, and our squishy bodies are decidedly not an exception.

> For me, I still wear N-95s on planes and in crowded places, I understand their effectiveness and it fits my risk/reward profile.

Likewise, however I should also add that in my case there's no risk component — not only because I get free FFP2 masks at my workplace, but also because it appears that one of the many ways that I'm unusual is that masks (and I mean this literally) cause me less issues than does my underwear.

Even if I wear a mask for a 31 km walk, it's the socks and underpants that pinch or restrict first, not the mask.