What’s spineless about not trying to change things you truly can’t change? Wouldn’t it be delusional to keep trying despite knowing it’ll make no difference? I think the important thing here is to distinguish between things you truly have no power over and things you can’t fix yourself but can still play a role in alleviating - or at the very least, behaving in a way that you’re not contributing to making them worse.

I think my personal worldview has some similarities to what you’re describing as radical acceptance. I don’t believe in free will, so no matter how much of a prick someone is being, I don’t blame them personally for it. I don’t act as if they’re choosing to be that way and could just as well choose to act differently. In my view, they can’t help themselves. They couldn’t have done otherwise. Of course, they’re not immune to outside influences, and I’m not saying they lack the capability to act differently in the future - it’s never people’s future behavior we get frustrated about, it’s their current and past behavior.

That, I simply accept as them being the malfunctioning biological robots that they are, and if anything, I’m deeply interested in how they behave. Like a car running without engine oil, I want to see how far it’ll get and what eventually happens. I do, however, move out of its path. While I might not blame someone for being insufferable, I also, for no free will of my own, don’t want to be anywhere near such a person.