The intention seems clear, but why decentralize data? Is it the only/best solution to data control?
What about simply creating a data coop (i.e. company) to own and control data, and sell memberships in it? i.e. solve data ownership with ownership rather than technology.
A central data coop would eliminate a lot of technical inter-linkage between different applications and repositories, and make everything much simpler. Would it not?
Such a data coop would be surrounded by a forest of application providers that have a single central data platform for sharing data among them.
It’s possible that there might be different competing data coops, if anyone is concerned about lock-in.