It's a bad example because the last 5+ years in UK/US have seen an epidemic of child vaping and nicotine addiction when it was illegal for them to have it, while the Tobacco companies fight tooth and nail against regulation on fruity flavours and bright colours.
I don't want to scrap laws. In Britain we're 20 years ahead of the US on this (see Gambling Act 2005). Gambling laws are written by the gambling industry so no parent should think that the law will do anything to help their child.