"It's so good I put my name on it..."
Why are most of the pro-Google+ testimonials anonymous?
I've described G+ as like going to a nightclub before 9pm: there's lots of space, but there's hardly anyone there, and they're all men.
I had a G+ account, but none of my friends, bar one, uses (or even joined) the service. I've a lot of "techie" and "non-techie" friends, and not one of the latter group uses G+; it's just not attractive to them - whether it's the google brand, or (more likely) the fact that "everyone's on Facebook/Twitter/Instagram anyway". The one friend I have who regularly uses G+, I meet regularly enough that I don't need to see his G+ feed.
... So late last year I deleted ("downgraded" in Google-speak) my account.
Just now, I logged into gMail, saw the "+ YourName" button there, and when I clicked it I found that my former G+ profile has been reinstated with all previous settings in place. Well it's certainly one way of boosting signups, I suppose...
(I don't own an Android device, and have never posted on YouTube, so it's not that)