Yeah but the main issue with Linux versus Windows was always that Linux was more difficult to get to work than Windows, you had to do magic to get it to work with your hardware, and it was much too difficult to get to use out of the box.

Android has none of these problems, it is on a large amount of devices (more than ios), it is as shiny as Apples, but it has developers loving programming it.

Heck Linux own the server market so completely, that the only thing that could reasonably replace it would be another Unix.