"Google Maps has destinations and directions. Not sure if they store histories of where people searched for directions. (Anyone in the know have thoughts?)"
They do have your search history. And if you've established addresses as "Home" and "Work" or others with Google Maps they have that too. They also have your social graph based on your emails if you or those you communicate with use GMail. And they probably have the addresses of those people you correspond with, over email, to use as destinations. And they have your emails to connect relationships across that graph when your Mom signs her email "Love Mom". And they may have your calendar to figure out where you may want to go on what date if you use Google for your calendar. They have street traffic information to let you know how long it'll take you to get where you're going. They may have your Uber receipts in your GMail to connect an Uber driver's use of Google Maps with your email receipt -- so they now may know at least some of the "who" was riding in which Uber at any given time.
Google likely knows WAY more than Uber does about its potential riders.
They do have your search history. And if you've established addresses as "Home" and "Work" or others with Google Maps they have that too. They also have your social graph based on your emails if you or those you communicate with use GMail. And they probably have the addresses of those people you correspond with, over email, to use as destinations. And they have your emails to connect relationships across that graph when your Mom signs her email "Love Mom". And they may have your calendar to figure out where you may want to go on what date if you use Google for your calendar. They have street traffic information to let you know how long it'll take you to get where you're going. They may have your Uber receipts in your GMail to connect an Uber driver's use of Google Maps with your email receipt -- so they now may know at least some of the "who" was riding in which Uber at any given time.
Google likely knows WAY more than Uber does about its potential riders.