Imagine having unrestricted access to meth. For the vast majority of the population, they’d continue to be productive members of society. For some, limited use might help them function better. But for a few, it would completely decimate their lives and impact the lives of many around them. They have absolutely no ability to manage their use, and oh, yeah, they’re also children.
Some will experience a significant down regulation of dopamine receptors caused by the constant artificial reward stimulus. As tolerance builds, more is needed for longer to get the same response, while the ability to function normally becomes more difficult. That’s screen addiction, not meth.
We regulate most things with that potential, even if it only affects a small percentage. About 1% of the population struggles with meth. 6-10% with internet related addictions and more like 40% among youth.
120 years ago, opium, alcohol, marijuana were a free for all. There was similar opposition to their control. Now it’s accepted as a public health benefit and most people would probably be shocked at how recent these became regulated.
My elementary aged kids can’t use “safe search” without being exposed to pornography, extreme violence, Five Nights at Epstein’s, flat earther’s, etc. Tech company’s have failed to create a safe product and when that goes on for long enough, the government steps in.
Worth pointing out that there are people (such as myself) opposed to the current drug regulations who will be put off by your meth example. The key detail is the part where it's being provided to children - in this case with the help of the school!
People will debate all day what should and shouldn't be regulated for adults but it seems the vast majority agree on shielding children from having potentially harmful things actively pushed onto them by strangers.