nostr:npub1u2hl9r48emg8eq82nh8zwadl3xr93u7vkk37qavfcg7cu3dmrrzqe4z4d7 

Very welcome.

Also, the two "nerdy" alternatives given are probably even better (XMPP, Matrix,) regarding safety.
It never caught pn and security awareness in the general public is next to non-existent.
There are also interesting Swiss and French solutions w/o any significant international reach.
Better to have a 90/95% solution and use it than having none at all.
This is why I think pushing #Threema is the best compromise, though #Signal has merits, too.