This was my experience with schooling as well. Sure I had my phone but it wasn’t what I needed to lose focus. The issue is how school is taught. I’ve had classes where I’m so focused and invested because of the professor and content. My mind wouldn’t even think about being bored. But some professors are honestly shit and don’t engage enough. Couple that with the general school environment and boom nobody wants to be there.
That’s my exact experience too. My school already bans phones, but that hasn’t stopped me staring out the window or just sitting there and thinking to myself. A phone would be an improvement as I’d at least have a chance of looking up something relevant to what the teacher’s saying.