I feel like web design animations are more similar to PowerPoint than folks want to admit. What I mean by that is that quick cross-fades can be used 99% of the time to tidy the look of UI but you rarely need to do anything beyond that.

Yells at cloud with visions of Windows 98 menu slide out animations stuttering on the barely good enough for the new OS pc! ;-p

YES. I love the examples here. The best one to me is the row background color transition on hover. It's painful, it feels like the UI is sluggish, when it reality it was someone going a little too hard on animation for no reason. Too often we think more animations = better.