@gabek @evan I think I have something that can fit your requirements.
I have been building cryptographic infrastructures for 30 years now, I made contributions to PKIX, WebPKI and SAML. For the past 4 years I have been working on what I consider the unfinished business - PKI for end users.
Since I can’t be bothered to do usability testing, I have adopted the principle that there must be absolutely no additional steps required to achieve security. So E2E chat must look exactly the same to the user as regular chat, which Signal showed is possible. Same for configuring mail clients for S/MIME, OpenPGP, etc.
I am currently working on adding end to end secure chat. From there, there is a really easy bridge to end to end secure voice and video by leveraging WebRTC. My original plan was for this to be phase 3 or 4 but I brought that forward due to the bird site fiasco and the UK criminalization of cryptography bill.
The Mesh is an open service so anyone can run a Mesh service, users of one service can interact with users of any other service just like with SMTP email. It is also possible for users to switch from one provider to another without switching costs. All the specs are open and the reference code is open source.
The protocol suite currently supports 2FA, contact exchange, bookmarks and password management, all completely E2E secure with a 2120 or better work factor throughout. It is not currently PQC but that can be added later.
My long term goal is to allow each Internet user to obtain permanent personal identifiers which do not expire or require any renewal fees. It is not possible to do this for free at a global level and do it right. But I can do it to an absurd degree of fidelity for $0.10 per name which seems fair in comparison to the cost of ICANN names. We will have to spin up a not for profit to manage that and stop people turning it into another yacht buying fund.