I think that's two separate battles which are part of the same topic. Battle #1 is combining the complexity and abundance of electronic devices with the time,

I think that's two separate battles which are part of the same topic. Battle #1 is combining the complexity and abundance of electronic devices with the time, dedication, and cleverness of kids requires (literally) writing a bug free operating system & application ecosystem as well as nearly every school employee having a completely accurate understanding of how to manage them. The goal here is never to get to 100% compliance but to add friction to noncompliance so it's easier for workers to do their job and get through the day. Battle #2 (the part these kinds of bans focus on) is on setting expectations for when electronic devices are allowed at all. Whether or not students always comply isn't even the goal of this battle, it's all about making the problem clear and swift to deal with: "I saw your phone during school hours so you're caught and it's confiscated" isn't about preventing kids from being sneaky, it's about making the enforcement easy.