A booster seat is designed to stop a child slipping under the seat belt that crosses their legs. It's not just raising the child up. They are very simple thoug

A booster seat is designed to stop a child slipping under the seat belt that crosses their legs. It's not just raising the child up. They are very simple though, essentially being polystyrene and some padding for comfort. It would be easy for an inquisitive adult to assess it's state but most people are far too concerned with other things to risk it. If you think I'm being overly harsh on the average adult then I refer you to the mass of drivers that pay hundreds of pounds for a car seat for their child and then text while driving. Humans are very poor at assessing risk.