Yes, but there are obvious limits to that. This is like someone who knows how to bake wanting to build a car, so they start making it out of dough.

That is not a good analogy. Games are built using programming languages. JavaScript is a programming language. Cars are built using metals (usually steel). A better analogy would be like trying to build a car out of iron, a really heavy metal. Since js/node is very resource heavy requiring transpilation/etc…

It's not a perfect analogy, but none of my comments are directed at the use of JS for a game, it's a fine choice. It's the use of Next.js that's the issue, it's a framework for server side rendering of HTML. It serves no benefit if your goal is to make a 3D game, it only adds overhead. If he had not been using it he would have realised there's a few bundlers out there that are far better than what Next.js dev server provided at the time.