There's obviously exceptions, when a car is well taken care of. I own a car that's 60 years old. But talk to any old timer, and back in the 50s/60s cars were expected to fall apart and be junk after 4 or so years.
I don't want to overly defend new plastic mobiles, because I hate them and only drive new cars when I have to, but they are better engineered in a lot of ways, from crash protection to engines and transmissions. They do last longer with less maintenance.
I mean, if planned obsolescence was introduced conceptually back in the 1930’s, then you have to assume it’s waxed and waned.
Generally yes, the longer you work on similar designs, the less you have to worry about to make improvements. But obviously, not everything we do is an improvement. When you stress one individual characteristic, you have to compromise others. Fuel efficiency is currently the main area forcing bad design choices, because you have to continually find more things to sacrifice in each change for diminishing returns while democrat retards form a cargo cult around the concept that investment can yield unlimited guaranteed returns.
I don’t have experience with cars older than the 80’s, but I generally believe that the 80’s were a time when American cars found their sweet spot, not because you never needed to work on them but because parts were cheap and you had ROOM to do the work, so you could keep them going as long as it took for them to rust to pieces.
Suddenly when the 90’s hit, American cars became ugly, cheaply constructed monstrosities and Japanese cars were cool looking and fast as shit if they had even a 3.0 6
Whatever gains have come back since the abortion of the 90’s and 2000’s have been offset by retardedness like every single model year of the mustang in the 2000’s using a slightly different configuration of brake proportioning valve, so if yours ever had the seals go, you better know a machinist. They don’t make that part anymore