Has the quality of children's entertainment plummeted, or do I just have nostalgia goggles?

[Agonized-Statism]

Hard disagree. IMO, the '90s and '00s were a dark age by and large: most of the cartoons I remember had really depressing settings and plots with tortured protagonists (Timmy Turner being shown that the world was better off if he didn't exist in the It's A Wonderful Life parody was a real gem), ugly experimental art styles, gross-out humor in every other scene, and a ton of sketchy showrunners especially on Nickelodeon's side. I guess the censors were too busy making sure Spider-Man wasn't allowed to throw a punch. Kids were locked inside by helicopter parents, but then they were completely okay with foisting them into a postmodern hellscape that presented a pretty bleak picture of life. It's not surprising that a lot of Millennials and Gen Z abandoned western entertainment for anime, and I have to imagine that the nostalgia for that era is some kind of Stockholm Syndrome. I wish I had shows like The Owl House and Amphibia when I was growing up.