figg

It's impossible to avoid. The Simpsons are entering their 20th season and have nearly exhausted all funny jokes within that particular environment, hence the show's decline. Family Guy was created partly out of the hype The Simpsons caused which is why they have nearly the same characters. There's only so many jokes you can do before you have to drastically change the environment which is what American Dad did with the inclusion of an alien near Washington D.C.. The Simpsons "stole" material from shows before it and so has Family Guy and American Dad, but I still like them all. There has been a dip in the comedy, but I don't think they're at a point where they're running out of material or anything.