That link you provided (which by the way is hosted on microsoft github in violation of his own principles) is very good! And repeats a lot of the same information from the simplified privacy site: simplifiedprivacy.com/signal-messenger-guide-to-a…
I am NOT saying the average person should be concerned with CIA spying. What I’m saying is that one should promote decentralized internet infrastructures that empower the individual over corrupt institutions, even though this threat model likely does not apply to you. XMPP is just as easy to use use as Signal.
If you use Signal messenger, you have to trust the Signal foundation, which uses Amazon’s AWS for the cloud. So you’re trusting CIA military contractors. I am NOT saying that Signal is a CIA tool. What I’m saying is that you are trusting and obeying a centralized authority, as opposed to being able to run code on your own server. And this contributes to the centralization of the internet and a loss of freedom.