There’s literally rules about this That we were all (hopefully) taught in drivers ed. in the case of 2 drivers reaching a 4 way stop at the same time the driver on the right goes first. If the two are across from each other then in most cases there is no conflict. In the case of them turning towards the same lane, then right turns have precedence over left turns.
These situations usually play out awkwardly and are always challenging. The really inexcusable ones, though, are where people just randomly sort of decide to violate the rules out of a spirit of generosity or something like that, like they're doing you a favor.
They only play out awkwardly because one or both of the participants don't remember the rules.
And yes, I agree with the inexcusable example you gave -- it's like the person who stops dead to let some car left turn through traffic. "Oh they've been waiting a while and I'm not in a hurry today I'll be a nice person" Yeah that's great for you but you just caused a damn traffic jam behind you and maybe someone behind you WAS in a rush. You just inconvenienced upwards of a dozen+ people to help one person. You were a net loss on society's progress in that moment.
I mean, sure if you could rely on everyone clearly remembering and following the rules every time or you could understand that humans are fallible and sometimes a bit of communication smooths that over.
