The assertion is not that something will inevitably happen because of this other than the further normalization of government authority over individual autonomy. That is an inherent result of this, as well as the prohibition of sale of alcohol and drugs to kids. You can argue on and on whether or not these are good, righteous, moral laws, but you cannot deny the intrinsic fact that widespread acceptance and even support of widening the scope of government control normalizes government control

Government already had the control. It's enforcing the will of the people, and the parents DO want this. So I don't see the issue.

Not sure who you have spoken to, but I don't know one single parent who wanted this. In fact most of them have said they will assist their kids to bypass it.

Government control is the only way to address corporate abuse, because they are the only body that have both enough power (to restrain corporations) and the possibility of being influenced by voters. Too much government control and you have a problem. Too little and you have no safeguard against bad actors.