Two of Apple's biggest rivals were also two of its most important partners with the iPhone. Google had maps and YouTube on iOS by default. Samsung manufactures Apple's chips and some of Apple's displays.
Cook has removed YouTube and Google Maps. Removing Google Maps could have gone better, but the idea is smart. Don't give Google too much information on iOS. It also gives Apple the chance to offer turn by turn directions for free.
As for Samsung, it is Apple's biggest smartphone rival and a legal nemesis. Yet, Apple relies on Samsung to make the iPhone. Apple is said to be in discussions with other chip makers. And DigiTimes reports Samsung is trying to win back Apple's display business.