Before my dad did the tracked vehicle transmission thing, he was an Engineer at a fan company, that the big-3 purchased fans (and turbochargers) from... He was on lots of cooling trips out to AZ, in these pre-production trucks, and employees of the vehicle companies would ride along (and/or drive) some times... This one particular trip (this was probably 1979), one of the high-ups at GM rode along (crew cab truck, 4 guys), and talked CONSTANTLY about how it was his mission in life at GM to dumb down the trucks, because nobody uses trucks like trucks any more, blah blah blah... Blabbed about this CONSTANTLY from Detriot all the way to AZ, and even while they were there...
When driving down a state highway in AZ, in the middle of one of these rants, they saw a guy in a mid-70's 3/4-ton Chevy pull out of a side road and head up a ~20% grade, WOT/redline in 1st gear, towing what looked to be a 40ft gooseneck flat bed LOADED with scrap metal... He said the trailer probably weighed 25,000#, from the looks of it... This was on a 110 degree day in AZ...
Everybody saw it, and nobody said a word... GM exec guy literally said like 5 words between that moment and the end of the trip...
So yeah... This has been in process since the 70's...
Mike