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-...
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).