Apple will happily tell you that if you want grandma to have a whatever color text bubble, you should buy her an iPhone, to name a recent example, rather than adopt the standard everyone else is using. I bought a Macbook last holiday season and couldn't even set it up until my wife set up her iPhone on my account to activate the laptop. I bought my wife a iWatch last week and briefly thought of getting myself one but you can't use it without an iPhone (they have a "kids" feature where a parent can activate it but it basically has no smarts at that point AFAIK).

So, for making an authentication standard, I'd trust Google over Apple.