That's not really true. It has to run a plethora of games well. Both new and very old. Not to mention emulators as well.

The fact that a different architecture might be a lot better than x86 doesn't change the fact that pcs and consoles use x86 and that all of the emulators target that architecture as well. I don't care how much better arm o risc can be, I care about being able to use the games and programs I want to use today. Unless new architectures are powerful enough to run x86 programs decently woth a translation layer, their adoption will not be widespread.