You guys have flawed logic. The manufacture rates the vehicles at what is safe. How is towing at max rating with a SUV any different the with a 1/2 Dodge Ram a 1 ton F350? They rate them at what they can do and warranty. You don't need a 3/4 ton ram to pull a log splitter or even a little 7K dump.
I towed Corvettes many many miles behind my wifes V8 2004 Mountaineer and my 5600# *******. All this on my 18' car hauler. It was plenty capable and safe. The shortest trip was 120 miles and the longest maybe 250. Yes, I had the big PowerStroke F350 but many times we had kids, dog, and belongings to take with.
As for what changed in the early 2000's start with disc brakes, more gears in the trannys, larger cooling systems and oil sumps, ect.
Chris