I don't, because I'm not in school, but my SO - who is a grade school teacher - says that there are problems in the school with students watching off-topic videos (analogous to "TV") when they should be doing other work.
In any case, distractions will exist, and continue to exist, students will seek them out, and this will forever be a game of cat & mouse.
Yes, and it’s fairly easy to hide an earplug by adopting a leaning posture.
Also we read comics and books, and played games on our calculators, exchanged paper messages etc., though you would classify that as active distractions I guess.
It’s true that smartphones are a different kind of devices, but I’m not sure it’s such a big deal if we account for the number of hours everyday they will be spending using them formthe rest of their life. Might as well have them part of the equation from the start.
Though. I do see your point and maybe in a few more generations it will seem like just another bump in the road. Can't say I am optimistic in any case.