Drunk-driving is absolutely socially condemned. Nobody lets anyone drive home after they've had more than one drink. Pubs are required to inform police / confiscate keys. I mean, honestly, it's a "lose all your friends" kind of thing in any sensible job / atmosphere / environment.
And seatbelts are mandatory. Seatbelts and airbags are fitted on all cars made for decades now. The culture is that basically everyone wears a seatbelt. People have had cartoons taken off air because they show Peppa Pig getting into a car and not putting on a seatbelt - they actually went back and edited them to show a seatbelt. Watch any British programme in the last 30 years. People wear seatbelts if they're in a car. It's only American movies, tv shows etc. (not even action movies but comedies and dramas) where I see people jumping into and out of cars constantly with no seatbelt even visible at any point.
It's nothing to do with any technology, though. It's to do with the culture. Drink-driving isn't socially tolerated, seatbelt use is ingrained in everyone from school.
Sure, we still have lots of other car-related injuries, deaths and problems, same as anywhere, but it's the culture that means we save lives.
I once was in a car in the front passenger seat while an Italian ex- was driving some family and there were two Italian kids in the back. They were absolutely resistant to the idea of seatbelts, because they'd been not using them all their lives. We made them belt up, and they didn't like it at all.
And I'm glad we did. At one point the little girl dropped her toy down the side of her seat. So she took it upon herself to unbuckle her seatbelt, OPEN THE DOOR while we were at speed, and lean out the door to retrieve her toy from the gap.
The ping-ping-ping of the seatbelt warning was enough to make me look round, and I had to literally dive across the car to hold her door shut, screaming at the driver to pull over, until we could stop and shut her door properly. I'm not exaggerating to say that she was INSIDE the door... between the door and the seat. If we'd hit anything, she'd be dead. If the door had blown open, she'd be on the road, at speed. We were close enough to opposing traffic on that road that the door would have hit the other cars and been smashed into her.
It's the culture, and what's normalised and what's not that determines where the biggest dangers are avoided. Just like US gun culture determines where their biggest dangers are.