Kids will tell you years later that it was wrong giving their data to Google, an Ad company, with core business of monetizing people's data.
Its the code that runs 24/7 what matters, Android or a few G services is of no difference.
> I wasn't using my data for anything
Browsing, location, contacts, photos of friends, calendar, emails... the lot. Goal is your full psychological profile, skills, circles, reactions, job positions. From as much data as possible. Uses today are simple ad targeting, maybe 3rd party screening checks. Tomorrow?
Hell. They would even browse Internet using Chrome signed in to their G accounts, giving away browsing history (all their secret dreams, interests that even closest people don't know about)
And these phones don't run Chrome at all.