Surely you're not claiming that the reliability of cars from the 60s and 70s is better than cars today. Is that what you're saying?
Yes since one of my cars is from the 70's and is giving no problems and I see many cars from the 70's still on the road. I wouldn't wager a lot of money on Hundais and Kias being still reliable after 150,000 miles but I wouldn't hesitate to take my old Ford cross country with over 250,000 miles on it. I wouldn't buy one of those "cheap" (they are not exactly cheap though) with over 100,000 miles or if it was over 5 years old.