Over 70% of all Porsche vehicles ever built are still on the road today

Probably because the Macan and Cayenne are not 20 years old yet.

There's a huge functional difference between something like a 911/Cayman and a Macan. While a 911 could be a daily driver for some people, practically speaking, they aren't. They are largely garage kept, driven infrequently during inclement weather, and are well taken care of because many people view them as "dream" cars. Even expensive engine out services are viable on 20+ year old 911s because someone is willing to pay $20k to have it fixed so they can have a "cheap" 911.

A Macan is a nice car, but it's still a warmed over VW crossover. People drive them like regular cars. They will get in accidents during evening commutes. They will see snow, salt, pot holes, etc. They will be driven 12-15k miles a year, versus the 1-2k of a 911. And these things will still be pricey to fix. These will age like BMW X-series: kept for short lease terms by the original owner, for the duration of the extended warranty by the second, then be recycled at buy-here-pay-here lots until an expensive repair sidelines them permanently.

The bottom line is a combination of the manufactured reliability of the car and the maintenance behaviour of their owners.

> Which Car Brands Last the Longest?

> Honda, Toyota, Hyundai, Kia, Acura, Lexus, and Ford all have long-term reliability. Certain vehicles are known to outlast others, however, each brand offers consistent reliability and longevity. What Is the Longest-Lasting Vehicle On the Road?

> A 1968 Volvo P1800 is considered to be the longest-lasting vehicle on the road with over 4 million miles across its odometer. There are also a great many million-mile cars, including a Lexus, a Nissan Frontier, and a number of others.

> According to one study, however, Toyota’s Sequoia SUV is more likely than any other vehicle on the road to eclipse 200,000 miles. What Cars Will Last 300,000 Miles?

> According to iSeeCars’ study on longest-lasting cars, Toyota’s indomitable Land Cruiser tops the list of cars more than likely to hit over 300,000 miles. However, it doesn’t say whether that’s the old generation used by many countries’ militaries, as well as the United Nations, or if it’s the newer, more pedestrian-oriented model. What’s the World’s Most Reliable Car?

> The one you take care of. Just kidding, but not really. As mentioned above, how you take care of your car factors into its reliability. In an official capacity, J.D. Power names the Lexus ES, which shares underpinnings with Toyota’s Avalon, as the world’s most reliable car.

[0] https://www.thedrive.com/cars-101/36055/longest-lasting-cars

Apparently it is a growth industry making fake '50s Porsches (and other "classic" cars) out of steel obtained from disused railroad beds, smelted before the steel all had traces of atomic-bomb fallout in it. I gather they actually cut the car literally down the middle and build up the other half, turning one car into two. (I doubt they cut the engine, but could be wrong!) And there is a profession now inspecting classic cars for authenticity that starts or ends with isotope analysis.

If I didn't know better, I would think the whole story was a hoax, because how could it even be possible? But apparently it is.