ummm, did you get the impression that i was beating around the bush? i stated exactly why i've personally needed it and have had to resort to polyfills even for the latest iOS.
> Intersection Observer can and will be used to detect ad impressions too.
yes, and? would you rather it be done using inefficient, non-passive onscroll, onresize and onorientationchange events with a bunch more MutationObserver and getBoundingclientRect() sprinkled in plus a generous helping of setInterval(..., 100) for UI polling? cause that's how things basically work today (and how the polyfill works). replacing all that junk with a normal, optimized API is exactly how it should be.
