The Simpsons has been around since 1989. To put that into context, the World Wide Web was born in 1990. This effectively means that The Simpsons predates the modern Internet, as we know it, by at least a year. With nearly a thousand episodes that have been aired since its inception, you can't exactly expect every single one to be great. Although most audiences (and probably even the showrunners) would agree with this sentiment, you might want to avoid calling The Simpsons past its prime when you're talking to the team behind the show.
The voices behind the animated characters of The Simpsons recently sat down with The Hollywood Reporter. Yeardley Smith, who is the voice of Lisa Simpson, shared her thoughts about criticism that she didn't like. In particular, Smith singled out how people keep on saying that "the show hasn't been good since Season 10", which she believes is offensive to the people who are working hard to make every episode of The Simpsons.
Nancy Cartwright, who is the voice of Lisa's brother, Bart Simpson, agreed with Yeardly. She describes such criticism as "mind-blogging" as she thinks of The Simpsons as a show that "still brings lightness and thought-provoking storylines" after all these years.