Educators who have enacted the smartphone restrictions said they help bolster student participation and reduce bullying but also raise challenges, like how to effectively keep phones locked up against determined students and how to identify and treat kids truly addicted to their devices.
This shows that taking away phones does get students to be more active in the classroom and erasing bullying is a big plus. The only downside listed is that it's hard to figure out ways to truly implement this because students will try to work around it. I think if there are clear improvements for students when this is implemented, it should be implemented more often. The down side I can think of is students not being able to reach their families, but that can also be done through phones at the office.