The operators can choose who to work with and can ban other servers as well as just other users. Many do this because the other server is too right wing, too le

The operators can choose who to work with and can ban other servers as well as just other users. Many do this because the other server is too right wing, too left wing, content illegal in some jurisdictions (the above mentioned pawoo is a Japanese server involved in the Japanese anime scene and therefore has lolicon on it), etc. Think of it like Twitter if the use of shared blocklists was standard rather than niche behaviour.