There's an awful lot of JSON that gets passed around. That seems a reasonable compromise between readable text and some sort of structure.
The keys 'mode', 'number of links', 'owner', 'group', 'size', 'last modified' would be repeated over and over again, stacked vertically.
Mode would remain an arbitrarily formatted string, or (worse) be broken into its own object for every attribute represented by the string.
A reasonably populated directory would fill multiple screens with cruft.
The formatting of the timestamp in the last modified field would still be an arbitrary string.
Comparing two files would require piping through another utility to extract just the appropriate fields and display them unadorned.
Sure, it might be moderately easier to consume in another program since you can simply iterate over a list and reference specific keys, but it's not really that hard to iterate over a list of lines and extract a specific field by number.
ls -al | awk '{print $5,$9}'
ls -al | jq '.[] | [.size,.name|tostring] | join(" ")'All right, maybe you do have a common tool that implements a query language so that you can filter out certain paths and objects from the JSON data into a thinner data set with known formatting expected by the next command in the pipeline. Then you need to write that command and you need more instructions, possibly again in another language, to describe what you actually want to do with the data now that you know where to find it.
At this point you typically write a separate script file to do this because it's easier to express in full-blown programming language what you want to do with the tree of hashes and lists and values. On the other hand, programs for lines of text are quite short and fit on the command line.
I don't see an immediate value in structured data, and especially none that would outweight loss in general applicability and usability in comparison to text based data processing.
Don't get me wrong: I would love to see a good prototype or sketch of how such a thing would work, and then try to imagine how I might be able to apply it to similar things for which I use Unix command line today. But I'm sceptical of "how" and also quite sceptical of "why".
This means you can give it JSON when you have JSON, but otherwise use the nicer format when possible.