I think the biggest thing is that his chin is REALLY small. It might be an art style thing but it looks really wrong on him and makes him look out of place and almost uncanny. Here's my attempt at a redesign.
Part of the reason I like Stylenny is because you already know that Cartman would be so fucking pissed that he's being excluded from his friends' gay polycule
when a certain trio tried convincing him to stop/acted like quackity starting a spanish channel to build two audiences and juggle english + spanish was weird ... and now they love being in spanish events since it benefits them. guess building a new audience wasnt a bad idea