Part of what you say may be true, however, my personal experience denies your assertions.
I do not live in the north or other region that has to contend with “road salt” but DO live in the state of Florida and on the beach where Sea Salt is a big problem for some people. I never had a problem with rust and still don’t though my Buick is a 2003 Century. I drove Oldsmobiles until they stopped making them. Now I drive Buicks. NEVER had a car repainted. My son, during the period you mention, drove a Chevy 4 W.D. pickup well over 360,000 miles. He had another with well over 300,000 miles and has just bought another Chevy 4WD last week. As a well driller, pulling drilling rigs is tough on a truck, and the terrain is anything but easy, but never caused him a problem with a Chevy. During that period he had friends and competitors driving Toyotas and other foreign marks changing their trucks constantly. He just laughed at them.
Anecdotal evidence counts for little in the larger picture. I have (had) about 25 yrs experience in retail auto business. Japanese cars from about mid 70’s on won the automobile trifecta. They were less expensive to buy, less expensive to operate and worth more on resale.
There is plenty of hard evidence to back this up.