Lastly, Signal doesn't collect/store any of your data on their infrastructure other than a few hashes required for operation. WhatsApp/facebook on the other hand collect, and likely keep, forever, at much metadata about you as possible. The only way to pay for this free storage is to stay more data so they can target you for advertising dollars.
This doesn't guarantee that Signal will live forever, but at the very least they've learned from previous mistakes and have taken actions to address them.
Most people use these apps for the network. The app without the network is useless, but any fork would initially be in this situation.
Your example of religions is also suspect. To be blunt we perceive it that way in places and times where established Churches are legally independent and separate from the government. It’s not always and often isn’t true, or at least isn’t the case by default in some places.
https://en.wikipedia.org/wiki/Church_tax
https://en.wikipedia.org/wiki/Tithe
https://en.wikipedia.org/wiki/Zakat
https://en.wikipedia.org/wiki/Jizya
Compare and contrast with Alms, the more charitable less compulsory concept:
https://en.wikipedia.org/wiki/Alms
Just one more reason to love separation of Church and State and the prohibition on Congress on making laws respecting an establishment of religion.
