I haven't read all these words yet, but I recognize enough of them to know I have similar interests. I was excited to see https://bazil.org/2014/04/24/introducing-bazil/. Of course, now defunct.
This approach is probably at the right level of abstraction, presenting itself as an actual filesystem that could become the default e.g. for a /home partition (computer) or a /storage/data partition (Android phone).
Too bad development looks to be halted indeed.