The thing is that age verification in a digital world is not easy.. what exactly does the government mandate as a valid verification method?
Like.. would asking the user their age be valid enough? ... because it's not like a reliable method exist (not even credit card verification prevents a minor from taking their parents card and go through it). IMHO, until the government doesn't actually set a standard, I don't see why websites should actually give anything else than the most minimal effort possible when it comes to this.