I don't know exactly what gets sent to google, but it's certainly enough to identify and track (retrospectively) a huge part of the world's population.
Now I know you get tracked by the celltowers anyway, but still. Navigation works fine with the accuracy offered by just using GPS and it doesn't need all the wifi scanning, it's pure data harvesting.
Yes, but theGoog doesn't own that data. By having all of theGoogOS devices scanning and reporting back directly to theGoog, theGoog gets that data for free. Plus, all of the other info it can hoover up that the cell towers would not have access.
However, you can increase gps accuracy using wifi. GPS is not that precise (part of which is government regulations) and WiFi does help immensely with accuracy.
You can argue that its a bad deal, shouldn't be allowed period, etc. But that is a different argument than saying that there is no scrutiny.