[l_zzie]

On iPhone, user-mode exploits remain sandboxed. On Android, on rooted devices, user mode code tends to be able to get root.

[vetinari]

Apples and oranges.

On iPhone, user-mode exploits may remain sandboxed, unless they break from sandbox too. On jailbroken iPhones, that last step may be pre-made for them.

On Android, user-mode exploits may remain sandboxed too, unless they break from the sandbox - same as iPhone. On rooted Android devices, the last step may be pre-made for them.

You can not compare stock iPhone and rooted Androids - just like you can not compare jailbroken iPhone and stock Android.