I personally wouldn't mind blocking those three specific ones but others obviously might disagree. I tried giving lemmy.ml the benefit of a doubt for a while but especially the worldnews community just seems disinformation & insults from the same accounts while the mods don't care or even actively work the same agenda.
I think what would be great is if we could block entire instances ourselves. Right now I am manually blocking all communities that pop up from those three instances, which is tedious. There is an URL for instances (Example: https://fedia.io/d/lemmy.ml), which even features the block button, but it simply does not work in blocking the actual content or even users of said instance. It would be cool if that was an actual feature and a link to the community's or user's instance available within the sidebar.