I think you're correct, but another piece of this is that students (especially in HS, but probably also in MS) have realized they can accomplish most assigned tasks in a fraction of the time using online resources (whether copies of old tests, agentic AI, or other sites), so they lean on their phone for this. A big piece of the missing equation here is the fact that home PC/laptop use has also been consistently decreasing, in favor of phones & tablets, causing phones themselves to be even more indispensable for youth.

I read a position paper last week suggesting the solution to this is to take a zero tolerance policy in the classroom and move all course testing back to pencil & paper / bluebooks. I would support that (as a parent of two current high schoolers).