The more there is known about you, the easier you are to be manipulated.
If you read George Orwell‘s 1984 or watch the Cambridge Analytica documentary on Netflix you get an idea.
That‘s why a minimum wage so low that you barely survive is so important
In Germany some schools offer exactly that in day schoolGanztagsschule.
In theory students get time to do homework in a dedicated hour and the last hours are filled with extracurricular activities.
But often times teachers assign too much homework and there‘s always at least one day when you have maths other sth else in the late afternoon, what‘s hell for everyone involved.
I wouldn‘t send my children there, but there are families who are thankful for this system and children who are capable to live an 8-4 day.
In the iOS Appstore you can see which data they want to obtain.