I will sit firmly on the fence. One size does not fit all. In the last thirteen years I have bought four new cars. All of them small hatchbacks. They have done the job. I did the sums with the first Fiat Panda on here, at the time I was doing about 25000 miles a year. I worked out the pence per mile over three years, I included everything, fuel, insurance, services, tyres, ved, and depreciation. It was cheaper than running my Volvo for the previous three years. In fact I could have thrown the Fiat away and still have saved money. (The Panda cost £6k and I got £3k for it at three year old). Yes the biggy was not depreciation but economy/fuel cost.
When I first retired I had a couple of old Land Rovers. They were very needy and constantly needed parts replacing. I know on the one I spent more than £3k in parts in a year.
I think the biggest saving is if you have the time, energy, facilities and competence to do work yourself. I don't anymore, unless it's very easy.
My everyday Panda is coming up to two years old and will have done about 27000 miles (thanks Covid) other than services it hasn't needed anything yet. I also have the ZX diesel estate, that has done a couple of thousand miles in the last few months I did get the glow plugs and relay changed on it. Then there is the Alvis which costs £80 a month to sit in storage, it's been out once this year and has a couple of £100 worth of bits sat in it waiting to be fitted.
I have forgotten the point I was trying to make, but as has been mentioned earlier: If nobody bought new cars there will eventually be a shortage of old ones