
In my opinion, critical, and important for a few key ideas. One is that it is onchain and impermanent. The second being the Web of Trust that comes from friends of friends, and second degree connections, which is unfeasible or violates unlinkabilty using semaphore.

There are many times you dont need to reveal, for which Zupass is perfect for privacy. The issue arrises when new people join our community, and it simply not enough to say, anon in our group referred them, or claims they have certain skills. A vouch is needed. 

Do you trust each of the 1000± addresses on the Zuzalu merkle tree? Would 10% of the wallets signalling in zero knowledge sway your decision? What about 20%? 51%

Or is it more important who? 

We can agree that knowing that Manu vouched Danny has "good vibes" or that ZackXBT vouches for my solidity, is both contextual and adds more value than inclusion proofs for an anonymised group. More so as we scale the community.

That said, vouching is both orthogonal and complimentary to Zupass. There possible usecases that call for vouching for encrypted proofs and published onchain, or that the vouch is offchain and encrypted, but left out of this scope. The 153 Bolivar experiments proved useful for self issuing an passport, something that is not trivial with Zupass, so will look forward to exploring how the two systems can integrate.