This makes it sound like smoothly animating a few rectangles is hard. The only reason it is true is because the web stack is, for lack of a better word, complete crap. It was fine for rendering static text and a couple images with no graphics acceleration, I guess.
Today, AAA games can redraw complete frames of 3D worlds inside of 16.66ms (along with processing physics / gameplay / networking / input) and I'm supposed to accept slow and janky GUIs on my desktop?
I just can't. I tried Atom, and even though it's usable, it's not exactly snappy. The complete waste of my hardware's resources makes me too sad to enjoy any good feature it might have. The web is stuck with this, that's "fine" but could we keep the desktop out of it?