Just my two cents, but...

I've been tempted to block a couple of people here - not out of any feelings of malice or vindication, but because I found their posts to be highly triggering. After I read that blocking people would prevent them to reply in my threads, I didn't do it. I don't want those people to know I blocked them. I don't want anything to do with them whatsoever. So I'd rather just skip their posts and resist the temptation to take a peek.

Anyway... I just wanted to show that there can be other reasons for blocking that don't really fall into the categories people were talking about here. I can see why it would be necessary to block people from replying in one's thread and derailing it, and I think that's a good idea, because it gives a lot more weight to the act of blocking someone.