It's too easy to do and can be done from quite far away. Also you don't need eyes. An innocent pic or video taken in public can capture that info.
I think long ago, Signal used to display phone number just beneath name when you are chatting someone. That always made me a bit uncomfortable. Now they don't do that, only displays name.
My understanding is that the coin stuff is still in beta and not available in the regular app.
Also when it lands on stable, it will be opt-in. So one need to deliberately switch it on to enable their cryptocurrency.
Their history tells us they go to great lengths to eliminate metadata. Court requests for signal data only get the account creation time and last access time. Please read about how they implemented their gif functionality in such a way as to preserve privacy. Also read about how they preserve your privacy in group chats. I think they are available in their blog. My understanding is that these things are unique to signal and apps like Element Matrix, WhatsApp, wire, telegram, threema, Conversations XMPP etc don't have it.
IMO it's a good idea to read Signal's blog. It can also be subscribed through RSS so you'll get notified about new articles.
But I think the new policy changes allow WhatsApp to read business messages. So be weary. Also I think you gotta accept the new terms to have WhatsApp Business.
There's Watomatic. Author claims it doesn't connect to internet even though it has full network access permission, so idk about it. But the code is FOSS. It's on fdroid too.
For Android, there is one from Peter Sanford (psanford on HN). He implemented the Go version of magic-wormhole, which I think is used by people like tptacek. So I guess it can be trusted.
Hi I'm not blind but wanna just dump some links here I bookmarked related to accessibility. Might be useful.
[1] The actively developed version of Mozilla TTS, named coqui-TTS. My understanding is that the original team was let go from Mozilla and they formed coqui.