Google's, but especially Sundar Pichai's, stubborness to make Android more PC-like to the detriment of Chrome OS meant that Apple gets to do multi-windows natively before Android - which should've had it at least two or three years ago.

Sure, Android M is likely to get multi-windows as well when they announce the final version (maybe), but we've still moved from Android getting some features two or three years before iOS, to Android and iOS launching very similar features about the same time.

This is a big problem for Google because Apple can release the new OS with the new features to 50% of its users within a week and to 85% of its users within a year. It takes a certain version of Android to do that at least 3 years.

If Google can't release its major Android features years before iOS anymore, then it needs to make upgrading Android devices by itself an even bigger priority, rather than leaving it to others.