You're asking parents why they might have trouble competing for their children's attention vs. a company with essentially unlimited money and some of the best programmers and marketers in the world? I sincerely hope you're being sarcastic.

By the way, I can almost guarantee you that your kids will find a way to get themselves smartphones before you officially allow it. Kids are resourceful, and there's nothing as tempting as something their parents tell them they can't have.