People who rob banks are not necessarily psychopaths. For a good (fictitious but convincing) example, see Toby Howard in the film https://en.wikipedia.org/wiki/Hell_or_High_Water_(film) Robbing a bank is universally illegal, but it is not regarded as unethical in general.
Robbing average Joe is universally considered wrong. Robbing bankers, insurance companies or other powerful subjects, I don't think so. It depends on the circumstances - for a good example, see the movie, that is, if you like such a mental challenge.
Have you heard of the Robin Hood legend? It says the man was robbing the rich, and was very popular with the populace. I find it hard to believe that his robbing activity was regarded as 'unethical' by 'almost everyone'. Or a recent example, the sci-hub and libgen projects. They are robbing publisher shareholders of their profits. Do you think those projects are regarded as unethical by 'almost everyone'?