Signal is not without flaws as you say, but if you have a phone number and can access a binary, there's every reason to believe it will securely and privately transmit your messages. You are also, ofc, free to fork their client and run your own service (as others have done).
Edit: to be clearer - signal both publishes a protocol (that is thought to be secure) and provides a public service (that claims to use the signal protocol). Signal has claimed that the binary blobs they add to their public client (and the other restrictions) are required to run a public service (anti-abuse, etc). You are free to believe them or not - I do.
At the protocol level, which you are free to use, none of the problems you or the ancestors have pointed to apply. All of the alternatives people are pointing to here are at the "protocol" level - accessible only if you or someone you trust has setup a node. There's nothing wrong with that - it's a good idea - but it's no reason to attack signal's service for not being a protocol (which they also provide).
[1] https://community.signalusers.org/t/overview-of-third-party-...
I've heard WhatsApp recommended from people I trust, but I have never personally used it so can't speak from experience.
Your suggested alternatives are owned by Zoom and Facebook. I'll stick with Signal.
All of them being tied to a phone number is bad form.
> Crypto thing they attempted
well...
Signal's "source available" infra can be self-hosted but it's huge effort and relies on a bunch of cloud-specific services which need to be replaced with self-hostslable alternatives. It's also extremely poorly documented and the code quality is fairly mediocre. I wouldn't recommend trying to host Signal infra yourself; it can be done; I've done it at work and it took some months of effort, and maintaining it is a nightmare (or was, then at least) because they'd only push one huge update to GitHub quarterly or less often.
[0]:https://www.theverge.com/2022/1/10/22876891/signal-ceo-steps...