The next step is rather to have personal end-to-end, peer-to-peer communication systems.

Which some platforms have, it seems, but then you're stuck communicating to only those within that platform. I believe ZeroNet has something similar, where you could technically email me at nxm9c2wjbjlhjsrc@zeroid.bit but I never check it because no one ever uses it. You can also mail me on I2P's network as well, at (I forget) @mail.i2p, but once again, it's network specific.

Whoever can get the major networks and up-and-comers to agree upon some sort of standardized P2P E2E encrypted mail system that can be accessed from anywhere, then you'd have a winner.

But I doubt that's possible with all the various networks working hard to implement their own vision.