The way that the ActivityPub protocol (this is the protocol that makes the Fediverse function) works is that it only pushes out content to instances that explicitly request it (a user follows another user/channel/community/etc, or the instance uses a relay), so the spread does matter and the ecosystem is kinda stuck with that until the underlying protocol is changed. I’d agree that a different protocol could remedy this, but realistically speaking I don’t see AP getting swapped out for something else anytime soon.