He's not basing it on any metric.
His sentiment can be chalked up completely to the nostalgia that all people feel for the era of their childhood. Everyone always thinks that "things were better" during the time when they were growing up - because they were too young to understand what things were like for adults in that time. The time periods of our youth always seem better than today.
I argue these are all things our society today would simply not be able to do if placed in the same circumstances. We are less effective.
What is this based on? Our society today is still capable of great accomplishments - look at what Google has built in 10 years, the amount of knowledge organized there.
I would argue that we seem to be able to accomplish less because as a society our ambitions are smaller. Large government programs get nowhere today because everyone fears socialism.