this reflects a poor understanding of how masks work to prevent the spread of COVID-19. Your unilateral decision is good but if others are not wearing them, there is still a great societal risk. The more people who wear masks, the lower the risk becomes.
Absent the kind of social contract you are describing, those of us at statistically high risk probably should consider wearing a respirator-style facemask in settings where both adequate ventilation and physical distancing are unlikely. Masks that comply with the Chinese KN95 standard (or at least that claim to) are now available to non-institutional consumers. (Those that comply with the similar U.S. N95 and European FFP2 standards still are not, as far as I can determine.) Respirators don't require bilateral mask-wearing to be effective: they provide a reasonable level of protection even to wearers who are in the presence of others who, for whatever reason ― ideological opposition, discomfort, or just plain ignorance ― don't wear a facemask themselves.
I wouldn't want to have to wear one of these all day long, as medical providers do; when adjusted properly, they provide quite a bit of resistance to breathing and the fit is very tight, so if you have skin that is seven decades old, as mine is, you'll see marks on your face when you remove the mask. But I can put up with that for a quick trip to our local supermarket, where most other shoppers do wear masks but a significant proportion either don't wear them properly or use home-made cloth masks that appear rather iffy to me: I suspect some of them are less likely to trap larger droplets than to break them into small ones, and thus disperse them over even greater distances.
I don't hold out much hope that we in the States will achieve anything approaching the level of voluntary compliance with common-sense infectious disease regulations that has been achieved in Japan, Taiwan, or South Korea, even if a new federal administration promulgates a comprehensive national policy, and the only other way to achieve the same result presumably would involve the kind of unacceptable draconian measures adopted by the government of China. So until there is a cure for COVID-19 or an effective vaccine, I'm afraid it's
sauve qui peut.