Most noise I can tune out. Invading my personal space it one that I cannot ignore, even before the social distancing I had no issue telling people to back up.
I'm not usually in situations where people get that close to me - maybe in an elevator. If I see there are a lot of people already in it, I wait for the next one. I don't like when someone is too close to me on a cashier's line either. Or when they keep hitting you in the rear end with their shopping carts because they're leaning on them reading the Enquirer.