Treeshaking imports (which, admittedly, I just learned about from some googling) assume that the JS you’re importing comes from another file (that the browser would have to fetch separately), yes? I believe that’s not a restriction of RequireJS (which I have experience with through my work but wouldn’t use on any personal projects.)
I’m just thinking performance-wise you’d get better performance by putting all of your JS in one (or a very few) files to be fetched from the server via one (or very few) requests. I am perhaps more of a stickler for shaving a millisecond here and there. (Which is part of why I wouldn’t use large JS lubraries. I wouldn’t want to make the browser have to load them.)