I’m sure we’d be forced to use it if we own an android phone or Gmail account
That's part of why Google's attempt failed so hard. They did force you to use it if you used several of their products. Comment on a YT video? Now you have a Google+ profile with that in its feed.
They basically created a social media profile of your activity, automatically, any time you interacted with a handful of their products. Like, WTF were they thinking?