Not at all. I made a similar move last month. My car buying plan is buy new, try to get 8-9 years out of it then trade it in for ~25% of original cost. I would hold on to them longer but the problem is everything starts to turn to rust from all the road salt. Buying slightly used just puts you closer to that 8-9 year mark when the rust starts to take over.
If you graph the cost per year of ownership vs. total cost you come up with two different answers. Purchasing new, then holding a long time, takes the new car cost and averages it across 9 years to hide the fact that the first year is the single most expensive year. Edmunds does the math for you here, for your benefit:
https://www.edmunds.com/toyota/corolla/2018/st-401730787/cost-to-own/What you can see is Year 1 has the highest cost; depreciation. However, not surprising, year 5 is also higher then average due to maintenance costs (new tires is required after a certain amount of miles, manufacturer recommended transmission flush etc.). Simply by purchasing a vehicle 1-2 years older will save $3000 over the lifetime and not increase cost/mile. Repeatedly doing that with 7 vehicles means you could get the 8th free (compared to buying new each time). 7 new vehicles would last (7*9) - 63 years, whereas 8 vehiclcles (8*8) will last 64 years. But....we neglected the time factor on delaying spending. Total lifetime costs show more back end spending with the used scenario (1 year old) and upfront spending with the new. Because we're smart mustachians, we can calculate the money saved over 64 years and determine the lifetime returns as well. If you do the math, a mustachian can also have car number 7 for free (compound interest is a beautiful thing).
This article below does the math poorly, its meant to demonstrate what I said above (with some poor math, I can already hear the complaints). You'll see your strategy of long term holding really benefits you. They do an okay job demonstrating the diference between purchasing higher and lower priced cars, the big mistake was not applying individual year costs and assuming all years have the same cost (forgiveble, that takes a lot longer and is high level)
https://www.doughroller.net/money-management/surprising-lifetime-cost-car-ownership/In short, if you buy 7 new cars over your life, I can purchase 6 (investing the difference and using that massive fund to buy the last 2) and get more years and miles by simply purchasing cars 1 year older and selling them at year 9, just like you. Upfront vs. backend costs are hard for the average person to comprehend, in short, delayed spending is better then upfront spending due to compound interest magic.
Note Edmunds assumed a cash price of $20,051 (bay area cash price, take up arguments with Edmunds) and 15,000 miles per year. Don't get fooled into arguing about price, its a red herring. I highly encourage you to keep detailed notes from your car and use that information to guide your next car purchase. If I'm right, you can thank me in 9 years. If I'm wrong, you lose nothing and can tell me so. I have no skin in the game, it doesn't change my behaviour if you spend less or more. Being right isn't important, figuring things out is what makes me happy.