I used to do it just like you did. I did my own maintenance, and kept a car as many miles as I could make it go, squeezing out those last miles, being held together with wire and duct tape. Not any more.
I buy new cars, and trade them in less than 3 years old.
I had to "rethink" my thinking. It used to be we never bought new cars, because "they lost 5k when you drove them off the lot". Check the KBB book value on a new one. Mine is more than I paid,
Also, people think "used cars" dont depreciate. They do. Try this. Look up a 2011 Sienna..with low miles. Then for research assume you buy it from the dealer, then take it and sell it to another dealer for trade in value. Yep, there goes 5 grand. That same 5 grand we said you lost when you buy a new one..well many times you lose 5 grand when you drive a used one off the lot now, and much less with a new one.
Its a fallacy that new cars depreciate and used ones dont.
I also notice, if you look at the "total cost to own" charts, how the maintenance goes way up, starting about the third year.
It would be easy to see someone who bought a real old car, and wound up making new car type payments "in maintenance and repairs"..so that saves no money. Its silly to put a lot of money into a car with 250,000 miles..you probably will never get that money back. All you can hope for is maybe get another 10,000 out of her until something else goes wrong. Of course, "car shield" and the like, is not a solution.
I checked, and on a 2021 (2 yr old) Sienna XLE with 20,000 miles is worth around 41k on trade in. While I bought all wheel drive, the fwd 2023 is around 44k new. That means you had about 3000 in depreciation over 2 years, That is less depreciation than most used cars, like I explained, above.
With a 2 year old car, it should be in warranty, so your repairs should be zero. Heck, you dont even need to change the oil, it has 2 years free oil changes.
So, I buy new cars and ditch them before the warranty is up, but I check to see how much less it will be worth than what i pay for it before I sign the bottom line.
New cars are the best buys now. Used cars are often more expensive. It did not used to be that way, but the world changes.