There has been a LOT more going on with design, manufacturing, quality control, cost containment, automotive engineering, competition, materials, technology … than just improved gas mileage goals over the past <insert a number> years. I know from a career at Xerox how much cheaper products were made in the 2000's than before that … to be able to compete on price. They don't last as long. The big thing now is that everything is disposable. The pressure in Engineering to continually make it quicker and cheaper is relentless. Its Capitalism. To try to be simplistic and pin it on gas mileage improvements is simplistic.
Having said that I have no actual numbers (I know you dislike facts and love opinion, don't have to restate that) but your "gut feel" is an interesting datapoint … of one.
That's all very true. Many/most companies products are not intended to last as long since they compete on price point and expect you to buy more . Maybe it is about to hit the auto industry.
The main reason cars started lasting-being kept- longer was that the bodies were not rusting out with giant holes as bad and engines were going way over 100k with no major or internal repairs needed.
It's not that I dislike facts. I just know that they are not always an accurate predictor of the chance of outcomes for every person or for one particular person - me or you. While statistics or percentages of failures etc are factually countable numbers, they are still too all encompassing to guarrantee you or I both with our possibly very different from the norm situation will experience with the exact same product.
Even being fact, they only give you relative likelihood.
I only double, triple, quadruple down on my opinion in response to other comments that seem to use past numbers or overall industry ones to be as exact of facts as gravity or time....heck, even those can possibly be relative or the effects not the same as the established norm or rule.
I'm sure I'll be called out on this too and told I'm "confusing" statistics or facts with some other term so someone can feel better.
I will just maintain that most everything is or can be relative.
I have started to see a little more rust on cars but I think that is the salt and brine solution they are using on roads. They still last much longer than in the 70s-early 80s but it's a scary trend though.