but the buildings did exactly as well as they should have. They didn't collapse in on anybody.
It's like a helmet, stops you get your head smashed in, after that it'll be weaker so you check it out and decide if it can still protect you or if you need a new one.
Compare this to the Napier earthquake in 1931 where hundreds died and thousands were injured and you can see how good buildings are today compared to the past.