A Question on the current working of iOS.

I'm pretty sure everyone here knows that despite the monstrous resources Android possesses, iOS is generally known to run with fewer jitters and the like. Not a diss, it's just that Android has a lot more background processes running than iOS does.

A lot of people on the Verge (and experts, and experts on the Verge) say that iOS is (for the sake of simplicity) tweaked specifically for the A6.

But my question is, does iOS simply need smaller resources to run? Would it possibly run flawlessly on, say, the Galaxy S4 because of the specs? Or is this just a misconception, and iOS simply runs best on an iPhone?

Thanks in advance, and I hope you didn't find this question extremely stupid/flame bait.