Well there was period where I changed cars every 2 years. For a total of 3 cars, and then I didn't need one any more. Not the most egregious example but I did like changing them. It's like any other toy, it's easy to get hooked on upgrades and trying out new models.

I drive them until the cost of fixing them significantly exceeds the cost of getting a new used car. Accounting for it being a pain in the ass to shop for cars etc.

But yeah every 3-5 years sounds about right for typical middle/upper class families. My parents did pretty well when I was little and I remember them doing 2 or 3 year leases.

I don't buy cars anymore. I didn't used to buy them either.