This post misses the entire point of JSON/TOML/YAML and the big advantage it has over databases: readability.
Using a file based approach sounds horrible. Context gets lost very easily, as I need to browse and match outputs of a ton of files to get the full picture, where the traditional methods allow me to see that nearly instantly.
I also chuckled at the exact, horribly confusing example you give: upd_at.
A metadata file for an object that already inherently has that metadata. It's metadata on top of metadata, which makes it all the more confusing what the actual truth for the object is.
I don't know if this applies to the entire EU, but home purchases need to be notarized. You can't just transfer a deed for a house without the government knowing.
I mean, Michael Bay is working on the movie, so prepare to see a lot more.