It's not the ban on cell phones and similar gadgets in the classroom that is troublesome, those should not be there to disrupt teaching anyway. It's the bending of curriculum to the daily political needs, promotion of groupthink masquerading as an honest academic debate, forcing students into classes they don't like just to fill the teachers' quotas, treating them as numbers etc. etc... But the marginalization of parental role is the worst; it's come to the point where a parent is treated as a potential enemy, as if a school cares more about the child's well being than a parent.
When you send a child to school, you are expecting that they receive an education. However, the way that school is done these days is way too regimented to have the children learn. They are treated like prisoners, having to be moved from class to class with bells like cattle.
In order to produce a suitable learning environment, students tend to lose freedoms, while in the constructs of a school system. Within a classroom, students may be asked not to speak or use their phones, which is a clear loss of freedom. This should not be alarming, because it is for the greater good and not a permanent situation.