Although, that’s just supposing South Park ends when Parker and Stone are done.
Worth pointing out that’s not quite so long as the other behemoth South Park is often compared to, The Simpsons, will likely have run.
Trey Parker turns 60 first, so if we’re assuming Trey also won’t be 60 yet before they call it quits, at max, South Park has nine or 10 seasons left in the tank.
At that point the show would be well past Season 30 which would be, suffice to say, a good run.