The main problem with Google is not that it indexes everything, but that it indexes everyone - since almost everyone (at least in US and Europe) uses Google. A

The main problem with Google is not that it indexes everything, but that it indexes everyone - since almost everyone (at least in US and Europe) uses Google. A strong competitor would limit Google's reach in this regard. In this particular case we could assume Google would know far less about iPhone owners. In longer term Google (and others) would have adapt to that limited reach: either by forcing its way onto iPhone somehow, or - hopefully - by not basing its offer on its vast knowledge about users.