I'd argue that South Park actually matured and toned things down on one hand, and amped things up on the other.

Their early episodes relied heavily on shock value. The later seasons are more nuanced, and rely less on gross out, bodily humor, or people laughing at cartoon kids swearing.

To think I was once taken to the principal's office for wearing this on a bart simpson t-shirt, which they told me to turn inside out. I of course refused, culminating in a very difficult day for the authority figures involved.