Signal is trustworthy, IMHO, but it has fundamental drawbacks for me:
1. It depends on AWS and Google #bigTech infrastructure. As #EU citizen, I prefer EU based services or even #selfHosting.
2. Even their desktop client requires to have Google Android or Apple iOS, which I don't have nor want.
3. They ask for a phone number to register. I don't like that.
Fortunately, all that has been solved 1999 with the introduction of #Jabber, the #fediverse of chat 馃檪