You don’t make sense. You’ve been told by me and even one of the admins that that’s not what you’re supposed to do. If you don’t like the content of a certain community, like those posting AI content, then you block said communities. Downvoting them would have 0 effect on you and your feed, other than being a waste of your time. Downvoting does not make the posts go away, it does not hide them, it just is a much bigger effort than just blocking the community, for literally no actual effect.
You can say the same thing about instances. Maybe there’s a reason someone made a community that follows the same topic? For example, a lot of new communities may be alternatives to those hosted on the Tankie instances, like .ml.