instant messaging - what to use?

[aphar]

I need an instant messaging app.
My requirements are

1. Runs on both phone and desktop, even when phone is dead


2. End-to-end encryption


3. Group chat support


4. Trusted vendor

Available options:

Vanilla SMS

Fails 1 & 2

WhatsUp, FB messaging

Fails 4: I cannot trust FB - huge corporation with political aspirations (fact-checking posts &c)

Google Hangouts

about to be disconnected (replaced by Google Duo which lacks text messaging), also - same problem (4) as FB - huge corporation with political aspirations

Telegram

Fails 4: Headquarter in Dubai

Signal

Looks most promising

What do you recommend?