FTFY
XP was simple, and a hit. Vista was confusing, and a flop. Windows 7 was simple, and a hit. iPhones are expensive, but simple, so users are willing to pay a premium. Android dominates the market for cheaper devices.
Windows Mobile is a flop. Windows 10 is simple, and a hit.
Oh, and remind me of the OSX and (50 Shades Of) linux total install bases again?