>What happens when parents don’t lock the liquor cabinet? When they smoke in front of their kids? When they leave porn laying on the table?

The state can't control those things, it can control putting an age restriction on certain websites. Unless you are advocating for the complete abolition of all age restrictions throughout society.

How is it more like leaving a liquor cabinet open than not buckling them up with seatbelts?

I'm glad we're discussing parental liability. It seems no one else is advocating for "social media access is criminal neglect," so I appreciate the novelty.