But here's a use case I had a few years ago. I was working with this system that needed occasional calibration from time to time from non-developers (read Product Manager or Technicians). The calibrations were stored in JSON, but JSON is quite finicky regarding syntax, specially when edited manually.
I implemented a graphical structured JSON editor that would take a JSON file, present you input fields to edit the JSON (input for text, checkboxes for bools, etc) and would allow the user to edit the JSON graphically and produce a valid JSON at the other end.
It was the tool I wish I had to tell the technicians to use when they needed to update things on the JSON file without manually editing the file.
I never published the project but it was really fun to work on it because I needed to handle the JSON in order, use types, and such things that JSON doesn't support so I ended up using Pest.rs, directly editing the AST, compiling to WASM... first time I using PEGs and such.
Best of luck with your project!