I post about music on my Twitter. Tech stuff here. Instagram for my hobby photography. Facebook itself is long gone. And all for the reasons you’ve stated. I use none of them particularly often.
I’m as left as they come, but I don’t trust that the winds won’t change or I will make a stupid decision, and my future is too important to risk that. And honestly I’m not missing much. If I want to talk politics, I do it with my friends over a beer.