There are always compromises some of them are hard to make. Signal successfully makes private / secures the “normal” conversations that would otherwise be on some Facebook owned app. None of the alternatives manage to do that.

Once you get Signal messages from randos without fist contact. Like airbnb hosts with password codes or IT admins or lawyers… it makes clear that they are doin it right.

Honestly it's just shame the platforms won't allow them to be the “native” sms app like iMessage. That would be the most ideal and probably upset much of the police deparments.