On the contrary if you are in a place where no one really works a normal job and things you bought or paid money to do are rarely topics of conversation then the interactions feel much more living.
I think the "golden rule" has been often misinterpreted as " treat people how you want to be treated" which leads to this misunderstanding that you called out. If we change it to being empathetic towards them and treating them how they want to be treated, the NPCs seem to become fully fledged characters.
Then it's obvious that I'm not one of them because their needs and wants are different from mine.
I don't want to get to far out there, like in Kurt Vonnegut's "Breakfast of Champions." The protagonist wanted to kill himself because he thought everyone except him was a robot.