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

A version of this thesis I've been developing: web3 is decentralized but people are not.

web2 centralization was a technical bottleneck to tribalism. Henceforth no more.