It's an interesting discussion... I suppose we'll never know.
Growing up when I did, 70s and 80s, typical cars were just really not built very well and would die for one reason or another around 100k... They'd have fatal mechanical problems or just rust out, or die in car accidents due to poor brakes, poor handling, etc. And all vehicles in the "rust belt" midwest and north east tend to rot out in a decade, probably never reaching 200k before being scrapped.
Given the abysmal build quality of most cars up until probably the 1990s, and the dino oils used, and the 'cash for clunkers' scam...er... program, I'd feel highly confident in saying probably most common older cars just never reached 200k. And you just don't see too many pre-1990s cars on the road any more. So that narrows it to mostly post 1990s cars.
My 3 vehicles with over 200k are at 2002 Tundra with 240k (bought used last year), a 1998 Ford Explorer with 203k (bought used last year), and a 2004 4Runner with 202k miles (I bought new in 2003 and put all those miles on it). So, 2 of mine are barely over 200k. So my personal average is right at 12k since 2003 primarily in my 4Runner.
To hit 200k in a reasonable amount of time, that's 10k per year for 20 years. The "average" driver used to drive 12k per year, but that's probably a lot lower since covid and "work at home" or unemployed. My average went from about 16k annually when I was on active duty, moving and traveling constantly, and going to a distant job (even factoring deployments), to less than 5k annually working at home. IOW, it would take me 40 years to put 200k on a new vehicle if I started today. I probably won't live long enough... So take a 25 year old who buys a used car with 100k and drives 5k annually "working from home." If that person kept the car s/he would be 45 to reach 200k... Figure, also, many people have multiple vehicles each or for the family so their family "carpooling" to events/meals, etc. or a person might take a truck today or a car tomorrow, so miles are being divided among several vehicle making one vehicle very hard to put high miles on.
Taking a 10k-12k average, most vehicles would have to have been built at or before ~2001-2005 to reach 200k. So figuring there's probably only a narrow range of cars that are of sufficient build quality in the window that realistically "could" be at >200k, in a approx 2 decade window from probably around 1990ish to about 2005ish. Anything older is either a collector (low miles) or in a scrap yard or been recycled (or rarely driven b/c it's not fuel efficient or it's unreliable, or not as safe, etc.). Anything newer than 2005, is probably just not driven enough to hit 200k. Now, what percent of vehicles, unknown.