Lots of stuff used to be built to last forever, designed for replacing common wear parts, or seals that would dry out.
TBH as much as the auto manufacturers initially complained about increasing safety and emissions standards, I'm sure now they are lobbying for more changes as it does give the illusion that a car is evolving constantly and really is a disposable and immediately out of date piece of tech once the new model rolls out.
For the key purposes of moving you in reasonable comfort, and efficiency, I doubt many cars now do much of anything better than 2000 Passat turbo diesel? Or a 4 cyl Accord from that era? NVH was pretty much sorted out in large and midsize cars by then, and engines were still pretty simple, but good efficiency. Passive safety has increased a lot since then, although auto death rates have gone up since 2015, so clearly the nut behind the wheel plays a big role.
I guess new cars are starting to be made for easier recycling, but its still a bit wasteful to also make them uneconomical to keep for 20 years too.
But the market wants what it wants, and the marketers and lobbyists try to steer the market to what makes the manufacturers money, so here we are.