Add to that, all the data collected on people unable to give proper consent. Every app a child would use(except maybe children's only apps) is collective metrics on everything and using that for aggregation and further sales(for them or for others). Then the "trivial entertainment" is designed to never get boring and keep attention at the expense of other activities. Even the brain games are only good at training to play that one specific game and nothing else. So the utility isn't there without the context of how to use a computer/phone as a tool