In the 50's your car would need a decoke maybe every 20k miles, now really not an issue. Much better fuel and oil quality, much better fuel metering with injection. Back in the 70's if you bought a new Ford Escort, Morris Marina or whatever you knew full well that the engine would be knackered by the time it had done 70-80k miles. So there were loads of engine rebuilders. Not so anymore. Most modern cars will easily do well over twice that, down to better manufacturing quality, better lubricants and so forth. What will probably eventually kill most modern cars is an electronic fault which either cannot be repaired, often because the parts are completely sealed and cannot be dismantled, or because the manufacturer no longer supplies spares and second-hand units are no longer about either. I am absolutely in agreement with you that we need to get out of this habit of always wanting new stuff with more and more gadgets, many of which serve little real purpose, and are just more things to go wrong. Already you see many perfectly serviceable cars going for dismantling because of some really stupid electrical issue that costs more that the value of the car to repair. This is only going to get worse.