JSFiddle - React, Tailwind, and code Playground

JavaScript

function cleanIt(obj) {
    var cleaned = JSON.stringify(obj, null, 2);

    return cleaned.replace(/^[\t ]*"[^:\n\r]+(?<!\\)":/gm, function (match) {
        return match.replace(/"/g, "");
    });
}

var obj = {
  name: "John Smith",
  favoriteObjects: [
    { b: "there's", c: "always", d: "something" },
    [1, 2, "spam", { f: "hello" }],
    { vowels: "are missing" },
  ],
  favoriteFruits: ["Apple", "Banana"],
};

document.body.innerHTML = `<pre>${cleanIt(obj)}</pre>`;