I've gone through quite a lot of cars, but only one of them because it was broken and not worth fixing. The others were due to circumstances changing, like moving country, or having a larger family.
That's not what service life means. It's a design requirement that is used to drive probabilistic models that determine longevity targets for individual components, and also reflects a manufacturer's commitment to support a specific model.
Yes, your car is expected to still run after 12 years. Some cars also run after doing 200k miles.
> It is crazy to me that people are getting rid of them after only 12 years.
Some people replace cars way earlier than that, either because maintenance becomes too expensive due to severe use (see Uber drivers) or because they simply feel like it. There's a reason where car leasing is a successful business.