The trend in my work is to add more and more JS to get the render time below 11ms per frame (11ms for my code, plus 5ms for the browser to paint and update, for a solid 60fps). To do that takes a lot of data structure design, memoization, cache management, plus a decent understanding of how browsers put things in the DOM and on the screen. Admittedly I work on something that's a bit unusual (a diagram tool for lawyers.. kind of like Visio-in-a-browser), but I can assure you that if you want robust, fast rendering it takes a lot of code to do it well. It is not bloat.