In the 60's, I use to change/swap cars every year or less but they were all junkers that only cost $100-200 because they were the only cars that I could afford. When they broke down and/or required too many repairs, I just sold/trashed them and bought another.
When I started to work and actually had some $ in the 70's-80's, I started to buy/lease new cars that I turned over every 3 yrs or so.
That stopped when I stopped earning "good" $, got divorced and took a job as an LEO in the 90's. Since then, I have only bought used cars, nothing "newer" than at least 3 years old when they had appreciated at least 50% below their sticker price.
My current stable includes a 2002 MR2 Spyder that I bought over 15 years ago, a 2002 Ford F250 that I purchased about 10 years ago, my 2008 335i that I bought about 7 yrs ago, a 2012 MB ML350 that I bought 3 years ago and my 2000 911 that I bought just 9 months ago.
They are all in excellent mechanical and cosmetic condition and I have no desire or intention to sell any of them. In fact, I'm thinking abouy adding another sports car to the stable.
Just need to find one the "right" one in the "right" condition for the "right" price.
OBTW, the MR2 only has 54k miles on it but the F250 has over 200k and the other 3 each have just over 100k miles on them and they all run FINE!