That’s really all any of Google’s “free” products are. Everything they do is to collect data to feed AdWords. They are an ad business masquerading as several other tech businesses, and all roads lead back to AdWords.
It's easy for Apple to say they don't link data between services when Apple offers no services of any particular value. Clearly Apple does not combine iOS data with their search engine, which doesn't exist. Then oddly it goes on to imply that separate sign-on for iCloud and App Store and iTunes are somehow benefits to the user when in my experience those are clear anti-features. I do not, ever, want to be prompted for my password when getting a free app from the App Store and that happens all the fucking time.
Forced system wide sign-in is probably the worse.
Being unable to use an email app for gmail without having the account fully associated with the device.
Are we supposed to be nice about our competitors in internal messages? Oops. Heck, I'm not even always nice about my company's own products, in internal messages.