The line about "forcing you to think in gradients and clip paths" is exactly right and I'd take it even further. When you only have one element, every visual trick has to come from the element itself, so you end up learning how background layers stack, how conic gradients can fake a pie chart, how border-radius can carve shapes out of a plain box. With 300 divs you can just brute force your way to a picture and never touch half of that stuff. The box shadow trick people call cheating is really just one more tool in that same toolbox, it's not somehow less pure than a div. I'd bet most folks who cry foul have never actually tried to build something with a single element. Once you do, you never look at backgrounds the same way again.