Smoking is a good example. I'm in my forties now, but when I started smoking aged 9, adverts for cigarettes were everywhere, both of my parents smoked & every shop sold cigarettes to children of all ages. It was normalised to a massive degree.
The question wasn't should I smoke or not, it's just what people did. By the time I hit senior school over 50% of my classmates smoked.
It's taken a long time, but now advertising cigarettes is illegal, you can't even see them in shops & have to ask the shop assistant to go into a special cupboard to get them for you (it's less embarrassing to buy porn, probably), they're sold in standardised packs I believe (I quit 6 years ago so don't see them anymore), it's banned in public buildings & in many public places & it has become almost unthinkable for children to even see cigarettes never mind actually get hold of them.
The attitude towards smoking has changed, mainly down to governments forcing the tobacco industry to be more socially responsible. People do still smoke, but the younger generations taking up smoking is massively reduced compared to 30/40 years ago.
Similar needs to be done with both drinking & gambling. At the moment if you watch any sport there will be an add break offering to help you place bets while getting drunk & ordering a takeaway.
People do have to take personal responsibility, but when the youth of today is bombarded with offers of alcohol, fast food and gambling at ever turn it becomes a standard part of life, almost expected of them, why on Earth should we be surprised when that has a catastrophic impact on some people lives?