I think it would make more sense to point to the Matrix protocol instead of Signal.
Matrix is actually decentralized like Email, allows any service provider as well as app provider - free to choose as a user.
It supports Perfect Forward Secrecy (based on the Signal Protocol), arbitrary many devices and "one verification for each individual".
Well, you might argue Matrix stores meta data server side (the ones chosen), while Signal at least doesn't have to.
But do you really want to give up all that freedom trusting a single service provider in that really no data is kept?
Maybe you can wait until Matrix allows you to avoid signing up on a server using P2P[0], then you have got it all, and don't have to commit to an alternative that has advantages, but also big draw backs.
Well, you might argue Matrix stores meta data server side (the ones chosen), while Signal at least doesn't have to.
But do you really want to give up all that freedom trusting a single service provider in that really no data is kept?
Maybe you can wait until Matrix allows you to avoid signing up on a server using P2P[0], then you have got it all, and don't have to commit to an alternative that has advantages, but also big draw backs.
[0] https://news.ycombinator.com/item?id=27077660