The purpose has never been to protect children; it's just a convenient motivation against which nobody would dare to object, just like mandating age restriction for porn sites is nothing more than an excuse to pushing further for elimination of anonymity, which started with porn sites exactly because nobody would dare exposing themselves for objecting to it. As I already wrote elsewhere, this happens while thousands of children are murdered in various wars, to their complete silence because going anywhere beyond the usual empty public condemnation followed by nothing would put them against very powerful foreign governments.