If there's a company, a headquarters, that a government can go to, then their software has a backdoor. Otherwise the company isn't allowed to operate. See the Telegram case, wiretapping laws in the EU and plenty of other cases. If there's a company and it's not open source, it's not private.
And I'll take it a step further: they're also working on infiltrating Nostr and Bitcoin. It's a level harder, and they're being really smart about it. These aren't fools.
Pay attention to which features they push that nobody asked for, alongside the ones people did ask for. Follow the money, where it comes from and where it goes. Nobody, and I repeat, nobody who doesn't fear God just gives away money for a "good cause". Nobody. They all have another agenda, often smuggled in like a Trojan horse. Lots of goodies with a little evil, lots of truths sprinkled with a few lies. That's how this shit works in real life.
Only a few at the top know the real agenda. The people underneath just kid themselves into thinking it's something else and go along with it.
The sooner you realize that, the better you'll understand the world.