He knows far more than me about this stuff, but maybe he's overthinking.
Maybe his point is that JSON is a plain text format. So it IS easily editable via any text editor.
But my understanding is that it is mainly a "container" format used for internet transmission. Why would you store it on a drive that way? (serious question - I don't knonw)
Don't "data" people more commonly use CSV as a plain text file type? (literally "comma separated values…. fancy name for obvious stuff)
So… same idea. It probably would be plain text…. for interoperability.