why would the native JavaScript not be something like (probably errors here, so like, not necessarily this precisely)

const div = document.getElementById('drawing');

div.innerHTML = `<svg width="100%" height="100%"><rect width="100" height="100" fill="#f06"/></svg>`;

obviously if the what is going in can have user input in some way then open to attack using innerHTML but otherwise it seems like the structure of the example native JavaScript is made in such a way as to make the SVG.js version seem super cool in comparison.