They can massage them to fit modern aerodynamic and pedestrian safety standards, though.

Ez: just mandate that pedestrians have crumple zones instead of cars

Nope its not health and safety, a lot of old cars can be refitted for roll cages and most of them are way lighter than current cars, thus making them need less large crumple zones.

Its not a supply problem since almost every car maker on the planet still has a supply chain for old parts. and since modern manufacturing is so adaptable the cost of retooling the factories is pretty much negligible in the grand scheme of things.

Its not a demand problem bc every fucking person on the planet would buy an old bmw or mercedes over this minimalist slop. Hell old audis or 70's renaults look sexy as hell.

No its a damn mentality problem. They dont want to make old cars since it would be admitting that modern cars are designed like a tweaker on caffeine spat all over the design board. It would be admitting that car design has declined over the past 45 years. It would be admitting that the top brass at these companies are a bunch of useless limp dick baboons who's biggest contributions to the company are limiting themselves one line of crack a day.

Thats the reason why, that there is no good reason why not.