Find a good GNU Social site, and bask in the freedom. it feels like Twitter when it first started.
If you don't like the rules of the red team (Mastodon) you can check out the blue team (GNU Social) or start your own team (or join the Japanese team)
Shared lists:
https://github.com/tootcafe/blocked-instances
https://github.com/MastodonBlocklist/blocklist
https://github.com/ticki/mastodon-blacklist
and others
What the previous poster was likely referring to is the 5-10¹ instances that are banned by most other instances with the reason "allows controversial content" or "Free speech zone"².
¹: the number banned varies from instance to instance, but it tends to be the same ones.
²: this one was used by an "anarchist" instance that appears to have more rules than most other instances.