The correct answer is the invention of the intermodal shipping container in 1955. All of the other factors mentioned might have played an effect but they were all relatively trivial. The effect of containerized shipping on geopolitics is one that most people don’t nearly appreciate the magnitude of.
Containerized shipping reduced the cost of transport by approximately a factor of 100 - 1000. Anything hooked up to the modern transportation grid can be transmitted to anywhere else so cheaply the costs are essentially free. Anything even just a few miles off the grid is more expensive than something on the grid on the other side of the world. Viewed from a logistics perspective, Shanghai is closer to LA than Las Vegas, Paris is closer to New York than Maine & Singapore is the center of the universe.
A definition of Quality used in several Quality Management methodologies is “customer satisfaction”. When the customers’ expectations change, the manufacturers need to change their specs, price, etc. to match those expectations - saying “oh, but my baroque chairs are so much better quality!” is not going to sell them to people who are looking for folding, stackable garden chairs; baroque chairs are bad quality for a garden.
So, I agree with your analysis on broad terms, but I think that it’s sort of the other way ‘round; US manufacturers blind complacency led to foreign ones being able to steal the rug from under their feet:
US manufacturers were used to being able to work exclusively on this huge, very homogeneous market, never bothering to look overseas (not all of course - but using your own example, a lot of those American car makers such as Cadillac or Buick didn’t sell further than Canada) either for openings or competition.
They grew complacent, and missed it when their customers’ desires changed… and in many cases, the change made desirable in the US products which had already been desirable elsewhere, and which were therefore already available: the companies which made them did notice the shift in the US market and start shipping their goods there - and US manufacturers were still building to specs which were desirable 5 or 10 years prior and which were not very desirable overseas (we did have an encounter with a Caddy in a secondary Spanish road once - Dad had to drive backwards for more than a kilometer until he was able to let that monster pass).
I’m not sure about the 1970’s, but my 1933 dining room set is doing fine..as is my 1925 bedroom set (solid mahogany). I also had to replace a made-in-China faucet (utter crap)-my ncle gave ne a NOS US made faucet (ca 1960-made of solid cast brass)-it is better than anything on the market today.
The fact is, the American people have been conditioned to accept crap quality goods-which is why we waste so much money , endlessly replacing stuff.
The perception has come all the way around. I’ve learned not to buy American products. It was American automobiles that taught me that. I used to be a buy American person due to my upbringing, and drove these vaunted cars from the '60s, '70s, and '80s. Then I bought a '80s German car, and later Japanese cars. I also worked for an American car manufacturer. One that had the maximum investment possible in a Japanese manufacturer, and the general view was the American co-designed vehicles were a step down in quality, to the point people wouldn’t buy cars from the Japanese manufacturer unless they were assembled in Japan.
To me the American manufacturing worker is part of the reason. While we didn’t do outright sabotage of factories like the British in the '70s, the general apathy and coasting on our reputation did. I’m not even positive that that reputation was well deserved in the first place. As has been said above, the US was the only one that had manufacturing survive WWII. I’ve compared my '66 Thunderbird (which was a $5000 luxury car in '66 dollars) to '66 Volkswagens and other overseas manufactured vehicles and the engineering was inferior. I can’t comment on initial quality or fit and finish.
Yes, I’m sure it is. Lots of things from the past last. And lots of things made today will last, too. But, of course, the fact that you have something from 1933 does not mean everything made in 1933 lasted, nor does the fact that something made in 2006 is crap mean than everything made in 2006 is crap. (this is especially telling when people talk about TVs; TVs back in the day broke all the time, whereas I haven’t had a TV break in years and years.)
My parents have a 40-year-old living room set that, structurally, is as sound as any house they’ve ever been in. They’ll last for a century. But every other piece of furniture they had back then is long dead. It would be sensationally stupid to look at their living room set and conclude that furniture in 1971 was awesome because, hey, this set survived, while ignoring the mounds of stuff they had in 1971 that did not.
The things we see around from 1933, or for that matter 1971, are by definition the very best-made things from that era; they survived because they were well made. The stuff that was crap is gone.
“There is nothing in the world that some man cannot make a little worse and sell a little cheaper, and he who considers price only is that man’s lawful prey."