One could argue that France is one of multiple examples that demonstrate that the technical parts of the problem are already solved. If we actually wanted to (IMHO we don't), had the political decision to implement global interchange of health data, and had solved the political problems required to get the resources and will to implement it, then we could just copy and deploy the solution of France or Estonia or whatever, knowing that the technical and organizational structures are reasonably appropriate, and there's no need to suppose that something fundamentally technically different is needed, there are no obvious technical problems that need solving.
I don't know who "we" are. But the solution proposed with the blockchains and stuff - misguided as I may think it is - had the goal of allowing general interoperability / portability of data among any providers, potentially across the world.
That France has some software that works well for their small corner of the world with their specific centralized model of healthcare is great for them, but doesn't solve the same problem. And it certainly doesn't mean you could necessarily apply it to the US, even if there was political will to do so.