I think it’s a good thing to have more than one community devoted to a topic. I have already discovered that I don’t like this or that community on this or that instance but I like another community on another instance dedicated to the same or similar topic. People have different styles and preferences even though they have similar subjects in common. It’s like having different supermarkets or clothing stores. Some like to get their jeans at The Gap. Others prefer Levi’s. Giving users more choices is good in my experience. It used to be this way in the days of forums and usenet news groups. I think if you’re not used to it you will get used to it. It’s like shopping around for a good class at college or looking for the right pair of jeans that fits you the right way.
You can block the whole Fediverse community. I did. Like, it’s helpful. I also blocked asklemmy. Also helpful. I haven’t blocked it on kbin, though. It doesn’t matter, I see shit I’m not subscribed to when I filter by “subscribed” still. I think filtering by keyword is going to be a long time away. You can be obnoxious as a commenter, though. When you see the keyword, say something contrary in a comment. That could be fun.