YSK: You can block communities from appearing on your "All" feed. just go to the website of your instance, pull up the community, and click "block community" (On mobile click "Sidebar" first")
Why YSK: You may dislike, disagree with, or be tired of certain communities and don't want them in your feed.
For WefWef users there isn’t a block button, however, switch to Memmy or Mlem and block them through that and it will also block in WefWef. Just wanted to throw that out there.