More builders now and better products. Funny how that worked.
The import invasion of the 1970’s was caused by the need for higher MPG cars. Those Jap imports were piles of crap. The Japs just listened to Deming first. That was the difference. Plus they had experience with making small cars. They got lucky.
Another point I’d like to make is how perverse it is for you to equate open markets with better quality; yet those same “high quality” imported cars that you praise were built and developed in Japan which is one of the most closed auto markets in the entire world.