Try thinking of it like the United States. Each instance (lemmy.ml, lemmy.world, kbin, beehaw, etc) is its own separate ‘state’ with its own rules and regulations.
This isn't the best example, american states basically have to play with the same rules for the most part, and can't leave the union. Keeping the analogy, the closest example could be the EU I think, especially with the Beehaw situation.
Pensé que era el único xddd