Yes, it is practically impossible, the same way there was a duopoly of desktop computers in the 90s and 2000s. Similarly to that era, there will be niche players (OS/2, desktop linux then, windows 10 mobile now), but the vast majority of the software and hardware will run the dominant OSes.

Hey, at least it isn't a monopoly and one of the OSes is freeish. Freedom wise, hardware is behind, but the software is ahead (of the desktop market).