Agree. It would be OK to make Signal able to integrate payment systems and make this thing compatible with that or with any other comm that implements the interface. Tying them together is pernicious.

Anyway Signal is itself pernicious by being tied to a phone number and to Google Play services, and by being very choosy about who gets ports.

I had high hopes for Matrix, once they got E2EE, but they have flubbed that by requiring a very heavyweight bounce server that won't fit on (e.g.) your typical home router or super-cheap cloud VM. Matrix should enable a place to keep your message archive independent of the bounce server, and allow gatewaying a non-public storage service via the lightweight bounce service.

But Element.io's business model is tied to heavy-weight bounce service.