> But none of those are simple key=value formats either.

What is the difference between:

    { object: { name: value }}
    { object: "{ name: value }"}
    object="name=value"

There's zero difference between any of them except how you parse and process the data.

> kubectl. Which to be fair defaults to output to a table-like format.

With line-based shell-variable output you have a line of variables and you have blocks of lines separated by an empty line (like an HTTP 1 header).

This can easily map to any table, two dimensions, or two levels of data structure without even quoting subvariables like in the example above. So, no, kubectl is not an example at least not how you've described it.