[artichokeheart]

Mastodon is only a client to the ActivityPub protocol. There are other clients that look more like Facebook.

But yes discoverability is an issue because it's hard in a federated environment.

[artichokeheart]

Actually StatusNet had a good solution for discoverability groups. An equivalent is an outstanding issue for ActtivityPub https://github.com/w3c/activitypub/issues/328