Farcaster is a single-tribe network, not a social network.

Big difference.

I do wonder how quickly networks need to become multi-tribe to stay relevant for the long term

One thesis is that we are entering the age of "network defect" — where the disalignment you get from squabbling tribes outweighs the advantage of having them all on one platform.

If so, we may need to make single-tribe networks more *useful* for doing things. 

Example: a designer guild network integrated with Figma

Interesting point. In addition to making single tribe networks more useful, we also need to create tools that allows for signaling membership into these groups.