It would explode sales of Mac. OSX on iPhone, people wouldn't need the separate Windows laptops they're used to. OSX on iPhone is the gateway for consumers into the OSX ecosystem.

And when those consumers want more powerful hardware, instead of buying a more powerful Windows laptop/desktop - they buy a Mac instead.

I feel like Apple knows this as well, so I can't figure out why they haven't pulled the trigger. Anti-trust risk? lol