If the average car on the road is 10.5 years old, and you assume a flat demand, it is consistent with the lifespan of all cars being exactly 21 years.

(if you look at a random sampling of 100 cars, 5 will be from this year, 5 from 2025, and so on until you've counted the 5 cars from 2005 ; the average age will be 10.5 years)

If you assume that there are more cars sold every year (due to demographics: way more humans are alive today than in 2005), then this is consistent with a useful lifespan of 25 years or more per car since the "10.5" average is skewed younger because of the age pyramid bias.

> One final factor that can impact how long your car lasts is good, old-fashioned luck. Unfortunately, luck is one factor completely out of your control. You have control over the way you drive, but not the way others drive. Even if you are a defensive driving expert, you can still find yourself involved in a car accident.

So the numbers are calculated including traffic collisions in the life span calculation.

I wonder what the actual number is if you exclude traffic collisions? "How often should I expect to have to replace my car" and "How long should I expect a car to last" aren't quite the same question.

Recent CATL independent battery testing has demonstrated 1.25 million mile longevity for battery modules produced. While EV uptake may take time, the EVs that are built will be with us for some time. That equates to 62 years of service life assuming ~20k miles/year