Nowadays, a majority of apps require you to sign up with your email or even worse your phone number. If you have a phone number attached to your name, meaning you went to a cell service/phone provider, and you gave them your ID, then no matter what app you use, no matter how private it says it is, it is not private. There is NO exception to this. Your identity is instantly tied to that account.
Signal is not private. I recommend Simplex or another peer to peer onion messaging app. They don’t require email or phone number. So as long as you protect your IP you are anonymous
Since when is encryption dependent on the service’s jurisdiction? When Signal has got subpoenaed it has always been incapable of providing data that involves the content of the conversation https://signal.org/bigbrother/
The app is also open source with reproducible builds (and you can use Molly instead, if you prefer) and when the clients of an end-to-end encrypted system are sound, that is all that matters to secure the content of the communication.
Audits are also performed as listed here https://community.signalusers.org/t/overview-of-third-party-security-audits/13243
I don’t understand where this doomerism comes from tbh, (online) privacy will cease to exist when either maths does or it becomes globally illegal to use encryption and the government’s intrusion is really so pervasive that they constantly know what you’re doing. Luckily we don’t yet live in that world, though the pressure is real and we are the first that have to fight for this basic human right