At the ends, there were (and still are) die-hards who use masks as weapons or as virtue signaling. At the height of the pandemic, masks were better than nothing. They were absolutely not completely effective at blocking the corona virus (news flash: no one said they were), they were just better than spewing material into the open air. A 40% improvement in the number of virus particles is still better than nothing.
On the other hand, yeah, people who are alone in their car wearing masks are doing it for reasons that are personal, and not scientific (well, unless they also suffer from severe allergies, are immune-compromised, etc). I suppose it'd be easier to figure out who's dumb if people with allergies or immune issues had to wear T-shirts, but what's the point. Some one else's issues have no impact whatsoever on one's own condition.
If you don't want to wear a mask now, then don't. There are few places where they're mandatory (maybe in hospitals?). There are still 500 people a day dying of Covid in the US; that's not an insignificant number. And if someone doesn't want others to think they're an asshole or idiot for not wearing a mask, then limit your activities to where those people don't hang out. Your rights don't, in fact, trump everyone else's in public spaces.
Wendy P.