WorstGen is probably the only active forum dedicated about One Piece.
You have fan theories, no censure, powerscale debate, battledome. I think it's great.
And also the main reason is whatever you find in twitter/youtube/any discord servers, it usually comes from here. Because many reliables providers, translators are also here like TAC so I guess those are the reasons why it's widely visited
Facebook is probably the most retarded one. You can see some biggest bs like Sanji === Zoro or Katakuri > Kaido.
It gives me cancer just by watching