Nonsense, most of my family and the people in the town I grew up in kept cars for 10+ years or 200-300k miles if they could. Some of my wealthier relatives drove 25-30 year old pickup trucks. If you don't think cars need to last 10+ years you're completely out of touch with regular people. Even if you're a rich person that buys a new car every few years reliability should matter to you, because lack of it costs you money. Reliability and maintenance costs over time are the reason a Toyota/Honda depreciates very slowly while a luxury car like a BMW/Mercedes depreciates like milk. The latter will cost the next owner a fortune in maintenance to keep running properly. If anything longevity should be far more of a priority nowadays since a) modern manufacturing makes it easier to produce long lasting vehicles than when we were children and b) anyone shopping for EVs and/or interested in environmentalism should be demanding longevity to reduce waste.

10+ years != “decades”, and the actual data is that cars last an average of about 12 years. Your relatives with 25-30 year old vehicles are the outliers here.

The first owner may not drive them for literal decades, but they should absolutely stay on the road that long.

That’s not a measurement of how long the first owner has them on average, it’s a measurement of the actual lifespan of actual cars.