They did Apple because Google orpahned their maps app on the iPhone by giving turn-by-turn navigation capabilities first to their Android app. Classic strategy tax that backfired as the most used maps app on Apple is the default app and Google has a fraction of the users on the iPhone.

Google also required user location data which Apple was not prepared to give. And Apple of course didn’t want to be in a second place position (apart from navigation there were also the better looking vector maps being reserved for Android etc).

Given the effect on early Android adoption, it might not have backfired.

You think a strong percentage of people switched to Android simply for maps?

A big factor in my switching from Android to iOS was Google Maps support coming to CarPlay. So I wouldn’t write it off.

Might've been a way to hedge their bets. Maybe they don't want their users' fundamental tools to all be reliant upon Google.

Maps is no different than search. Google lose plenty if they don't get iOS users.