Aggregation and distribution are virtues of large communities, not small ones.
The sophistication of Facebok's business is what allows the creation and distribution of content. I agree that if Facebook, Snap, Pinterest, Reddit, Nextdoor, Twitter etc, didn't exist, small communities would fill that void...
But they would do through a fragmented and siloed user experience that is hardly discoverable for the majority of the connected world.
This is the equivalent of running a taxi business vs running an airline. Sure, a taxi can fulfill several transportation needs but it could never replace what an airline does.