Good analysis
"It's funny how Windows operating system has always been known for being resource heavy and the most popular while Linux and Mac OS have always been known for being much more quick and light on older hardware."
That's because Microsoft kept insisting on trying to make their old Windows kernel keep functioning in ways it wasn't built to. With the Windows Phone OS, they finally did what has been LONG overdue: start from scratch.
It's amazing how much you can do when you don't start with megabytes of baggage!