If that were the case Molly FOSS wouldn’t exist

I'm not speaking of hard dependence as in "the app can't work without it." I'm speaking to the default behavior of the Signal application:

1. It connects to Google
2. It does not make efforts to anonymize traffic
3. It does makes efforts to prevent anonymous sign-ups

Molly FOSS choosing different defaults doesn't change the fact that the "Signal" client app, which accounts for the vast majority of clients within the network, is dependent on Google.

And in either case -- using Google's Firebase system, or using Signal's websocket system -- the metadata under discussion is still not protected; the NSA doesn't care if they're wired into Google's data centers or Signal's. They'll be snooping the connections either way. And in either case, the requirement of a phone number is still present.

Perhaps I should restate my claim:

Signal per se is not the mass surveillance tool. Its ~~dependence on Google~~ design choices of (1) not forcing an anonymization overlay, and (2) forcing the use of a phone number, is the mass surveillance tool.