I think very few people on this forum disagree with this.Here's one: I'm not sure how an aging fan outgrowing The Disney Channel, Nickelodeon, or Cartoon Network is somehow The Disney Channel, Nickelodeon, or Cartoon Network's fault. The reality is the quality control on all three networks has been remarkably stable over the decades. Yes, there is a lot of garbage. But you were watching similar garbage when you were younger, and and you were simply too young to recognize it as such at the time. That's not the fault of Disney Channel, Nickelodeon, or Cartoon Network.
A channel's likeability is more than just stable quality, though. In recent years, Cartoon Network has been narrowing its audience a lot by making cartoons that are very similar in terms of target audience. Luckily, Tom Ascheim is going to change that in 2021.
The problem with Nickelodeon is not a decline in quality but rather a decline in amount of cartoons.