theNetherlands

I would go into the specific points, but really none of this invalidates my main point that Signal is a marked step forward

We are going circles but I will repeat it: Signal isn't immutably better than WhatsApp, it only happens to be more politically-aligned with your beliefs (which we share in large parts, to be fair!) at this very instant (and we saw that this can change without notice).

My threshold for justifying a mass-exodus out of a popular messaging system is that 1- it offers non-revocable privacy and security guarantees and 2-, that it doesn't lock its users in a single vendor/single service provider. Those two things combined are important, because they would finally give the chance of breaking away from the never-ending cycle of "enshittification → exodus → unsatisfactory explorations → painful rebuild(s) → monopoly consolidation → user captivity → enshittification". Anything else is a slight variation around the current disappointing status-quo. I don't think it's too far-fetched, and we really deserve this "luxury" for something as fundamental as instant messaging. I can only hope that you understand why I'm not willing to compromise on that.

I'm also willing to bet that, with the rumbling going on in the USA at the moment, Signal might sooner or later become a target of/re-align itself with the new "administration". Maybe then you will sense more of that captivity I keep rambling about?

My point was that you’ll be communicating with people each of whom chose their own service poviders, and thus you’re also trusting those.

The worst thing the other server can do is drop your messages silently, which you will absolutely come to know. Think of XMPP with end-to-end encryption as essentially encrypted email. "What if I can't trust the other server at @bizarre_email_domain.org? Whatever."