I think the debate here is what "editable by humans" means. If you're using a tool for editing JSON like VS Code, I don't believe you're really editing it by hand. You're using a program that has specific things for JSON that give you to have a pleasant experience editing. I believe editing by hand means using a standard plain text editor and it's a lot worse.
Formats that use braces are relatively easy to parse by machines but can be harder to read by humans. Utilizing white space makes things easier for humans to read. A JSON file could have everything on one line. But something like YAML it forces you to use white space and new lines which helps humans to read it.