> subordinates must show their dominance

That's how to get fired. If the boss says "do it" and you say "no" and you each hold your ground, eventually it gets to "do it or you're fired." (In a few companies it might be "do it or you're fired" vs "stop asking or I'll transfer" but it's rarely "stop asking or boss is fired.") A good boss won't let it to that, but that power over another—to hire, promote, and terminate—is what fundamentally defines the hierarchy.

Giving you the benefit of the doubt as to who was toxic at those jobs that ended badly, it still sounds like you're significantly more assertive than most workers. I do agree that people should stand up for themselves regardless of their position in the hierarchy. There's no excuse for mistreatment, and especially these days, consider how someone who's mistreating you may mistreat someone who's more vulnerable.

That's why when any boss asks for something completely irrelevant for the job, in my opinion the correct approach would be to ask for a documented request. i.e. "please, send me an official email with your request". If the boss then goes crazy, then reveals he had no good intentions from start, and yes, it's definitely hard to fight back without eventually get to that point of no return. If that's the case, you then better leave that place before getting fired, which has the side effect of showing that you're not that easy to manipulate. It's not just about self esteem and/or testosterone however: any time diverted from the job to other things could impact the project, and doing that during your time means there's your name stuck to the job at that time; if something goes wrong because of the time spent doing other stuff then it is your fault, so he better gives some good official explanation for demanding that extra work.

(edit: moved under the right parent post)