People get to decide who they do and don’t want to talk to.
Online, part of what that means is that people can block each other. People who don’t want to talk to each other can make the conversation stop.
If someone blocks someone else, all it means is that they’ve decided to stop talking to them. In almost all cases, you have every right to do that.
Blocking someone doesn’t mean you’ve lost an argument. (Similarly, if someone else blocks you, that doesn’t mean you’ve won or that you’re better than them.) It just means that you’ve chosen to stop talking to someone.
There’s nothing wrong with ending a conversation. You don’t have to interact with everyone who wants your attention. You have the right to have boundaries and you have the right to use technology to enforce them.
The only time it’s wrong to block people is if they are entitled to your attention for some reason. That’s rare, and mostly applies to corporations and elected officials.
Blocking is not a punishment or a confession of weakness. It’s a boundary.