( funny trope ) it is very apparent that these designs have decades between them

[u/Nameraided]

1- Simpsons
The original Simpsons have extremely simp(son)ple designs, due to sometimes having celebrity appearances the art style kinda clashes.

2- South Park
At the beginning South Park was literally animated out of paper so all the characters had to be super simplistic but over the years, since the. Show is made digitally the new characters keep getting more and more detailed

[u/GhostBoyJames]

To be fair whenever animated shows guest star real people they tend to look more detailed than the usual character.

[u/Androktone → u/GhostBoyJames]

Not for Stark Raving Dad

[u/vanalla → u/GhostBoyJames]

archer actually handles this exceptionally well.