Perfect candidate for a nice, simple, self-contained web component / custom element. Instead of:

    <div id="json-tree"></div>
    ...
    const container = document.getElementById('json-tree');
    container.innerHTML = generateJSONTree(jsonData);

    <json-tree id="json-tree"></json-tree>
    ...
    const container = document.getElementById('json-tree');
    container.jsonTree = jsonData;