I'm not into Family Guy at all, but I still gotta say that at least it's got its detractors. South Park has been a tediously obvious dead-horse meme generator for the last ten years, and it still gets held up as the modern gold standard of satire just because it has the courage to say "Hey, both sides suck" amidst all the gore and gay jokes. I think when Matt and Trey admitted they identify with Cartman most out of all the characters is when it went sour for me.
I liked the South Park episode where they beat up on Family Guy. You might say that's a fight where everybody loses, but I thought South Park zung them pretty good.
But I agree that "both sides suck" is a cop-out if you're gonna claim to be a satirist.
That particular ep was pretty funny, yeah - and they could still nail a thing or two pretty well the last time I checked in (I loved how Al Gore wore a cape & went around with his hands outstretched, like a little boy playing Superman), but I haven't been on board with South Park for a while, for similar reasons, meaning the "both sides suck" argument.
What I also started to not like was their "either it's all okay, or none of it is" stance, and not only their stance, but the fact that Matt and Trey would regularly run pell mell towards that stance. The fact is it's not all okay.
Also, they're very proud that they can get an episode out quickly about some hot button issue & be the first ones out there to make a comment about this - but then, they usually go back to "both sides suck" as their statement.
It's like that old cliche about clients who say "we want you to design our product, and we want it to be good and cheap and we want it fast." The designers go "okay, pick two of those things".