Masks always provided some benefit both ways, but the benefit is maximized if everyone is wearing them. N95s and similar have started to become more common, and those have substantial benefit to the wearer, even in a crowded room of unmasked people. If I am wearing an N95 and you are not wearing a mask, I am more protected than if both you and I are wearing surgical masks.
This was my understanding about surgical masks pre-covid, but I plan on wearing a better-sealing (KN95, KF94, N95) on public transportation, airplanes, and in busy places like supermarkets for the rest of my life. If I can avoid even 10% of the colds or other viruses over the course of my life it seems like a very worthwhile tradeoff.
Every year I travel to the east coast for Christmas and every year except this year I've gotten sick during travel. I'm happy to normalize masks cause I want to wear them on planes to avoid feeling miserable the whole time.
You can actually get some protection wearing and N95 mask. Though those aren’t popular in the west because they often have exhalation valves that make people paranoid (the CDC says they are ok since they allow for a better seal and are filtered).
According to this large randomised trial [1], simple interventions to increase the use of surgical masks reduced infection by 11%, and by nearly 35% in over 60s.
That doesn't seem useless.
Of course, if you're only talking about protecting yourself from others, then a KN95 mask is clearly the way forward.