I'm really not sure if it's possible without sacrificing privacy or security. For instance, PGP isn't used en-masse either. We do see (alleged) e2e encryption in most messengers though; but it's definitely less secure and private than PGP, because often they can't be audited, don't have verifiable builds and there is no key exchange through a manual web of trust.
What do you think about OMEMO encryption used by XMPP protocol?
It is using open standard based on the Double Ratchet Algorithm, and it is said to have better encryption compared OpenPGP or OTR and it's much easier to setup.
I am not trusting any obscure encryption that is offered with telegram secret chat or with viber.