I really don't see the point of hearing people complain about problems they don't want me to fix.

If it's an intimate partner my patience for this is much wider but if it isn't I find the best course of action is just to say: "listen, I find it stressful and anxiety-inducing to hear about these problems all the time, and I'd prefer it if this isn't a topic chat came up in conversations"

You have agency in setting boundaries, and listening to someone piss and loan constantly about shit isn't where mine begin.

I just can't. If it isn't us versus the problem then it's you versus the problem so keep me the fuck out of it.