In it's heyday the Seinfeld characters had taken on lives of their own, their adventures each week were anything but predictable. The unpredictable, creative atmosphere opens the viewer to accept new plot twists as well as to new ideas. As with South Park and the Simpsons, Seinfeld was a relatively vulgar and in your face show. It sure does, animation allows the depiction of things that would be wholly unacceptable in live action. Although it is not as realistic, the human imagination is more than capable of filling in the details.
Animation can push the boundaries for the rest of the industry.
We see that animation can act as the vanguard for eliminating social preoccupations. So in response to the opening question, are animated shows better. Well in respect to the fact that they are innovative, creative, irreverent, and hilarious, yes.