If the goal of school is to develop children into young adults with good reasoning and analytical skills, a basic wholesome world and social model and some practical skills and basic physique, smartphones seem to contribute little and distract a lot from those aims.
I agree with your take on the purpose of schools and that smartphones contribute little. But my concern is that actions like these teach students an additional lesson: That it's okay to coerce people into specific actions or forfeitures if it serves your purposes. Children and teens absorb a lot, and while they don't always absorb the contents of their lectures, they do typically absorb how they're treated and how th…
Is there any precedent for this that we can model / reproduce? Any country or region where students are considered academically successful, while having unrestricted access to the internet in their pocket?
If it exists, it would be very worthwhile to understand what gives those students such strong self control. Do they do it on their own? Are they somehow admonished/shunned publicly for that behavior?