> I genuinely do not understand where this impression is coming fron.
I don't want to engage in a citation battle, I just can't care enough for that. Having read those posts about Matrix, XMPP (OMEMO) and a couple others, many months/years ago, they really came across as "screw those amateurs for even trying, Signal is great, and by my very definition of it, only Signal can be".
Again, those are not your words, but something about the tone and the way you compare them made it sound that way.
Also, even if that's besides the initial point, I firmly disagree with the premise of the post you just linked. For the same reason mentioned in a sibling comment stating that the real world isn't binary even though IP addresses might be: A centralised service is political no matter what. If not their admins, their hosing provider or executive power may decide to censor you based on your country of origin, political beliefs, ideological activism or any other reason out of your control. Signal's crypto protects what's in the envelope, but does little else (neither can it) against a motivated state-actor fingerprinting you beyond the service boundaries, and guess what, we know it to be a fact for the jurisdiction Signal is operating under.