Good usecase for Solid (https://solidproject.org/).
It seems like an interesting project but I wonder if it has any chance of reaching critical mass. The incumbents have no incentives to interoperate with such a protocol as far as I can tell.
I really wish something like this Solid protocol would succeed, but I don't see how you could generate enough momentum for it at the moment.
ActivityPub?
Matrix (before they landed their gov contracts etc)?