[lttlrck]

Yep.

"comment": gets littered across the JSON... or temporary changes are copied and the original property name is invalidate with a prefix. The simple structure is gone, replaced with adhoc workarounds.

Similarly when you want to use a type not supported by JSON such as datetime or binary data, you might end up with "type":"binary" and use base64 or whatever in the value (shoehorning attribs) - when it really needs a schema to follow during parse and stringify. Or OpenAPI, which is hardly lightweight and really doesn't match the simplicity of JSON.