A meaningless advantage.
Apple does not compete with Google to distribute apps on Android and Google does not compete with Apple to distribute apps on iOS.
The value (to consumers) of the App Store is not that it is so locked down, but rather that it is the only way for people to put apps on the phones they have already bought.
But wait, you might say, Apple actually can open an app store on Android and compete with Google now!
But c'mon, it'll be a cold day in hell when Apple helps make the case that these rules should also apply to them.