Pixar stopped making movies for kids and starting making movies about kids.
I would say these movies aren't so much "about kids" but they are about grown ups imagining themselves as kids again, as it was the case with Lucca and Turning Red, both movies drawing heavily from the directors' childhoods. The diference being that they are tapping in personal experience to describe a phase of our lives in a broader way, which is fine, but this sort of storytelling is more appealing for adults, more specifically adults at the same age range of the creators, than kids themselves.
To put in a blunt way, manchildren filmakers making movies for manchildren, hence the heavy sense of nostalgia and emphasis on the sentiment of "what was like to be a child".
But there is abig problem with that, the ones that can "understand" what was like to "be a child" are people who are no longer children. Kids don't give a fuck about "what is like to be a kid" nor they particularly care about kid characters.
The first "kid protagonist" Pixar had was on their 5th flick, finding Nemo, and even that is debatable, because Nemo ain't that much in it, the movies is more about his father.
And even when a kid movie has a kid protagonist, usually it was about the kid going on a adventure and growing up, not a recollection of reminiscences undercut by a longing for those days meaning.
Not the biggest Ghibli head out there, but one of my absolute favorite movies is Castle in the Sky:
And the heroes are kids, but the movie doesn't waste a single frame on anything else but just the adventure, Boy meets girl, they go on a adventure, they find a ancient floating city, bad guy wants to take over the world, the kids save the day and fly into the sunset.
If Miyazaki was drawing from his childhood when making this movie, then he kept those cards close to the chest, because like I said, Castle in the Sky is all about that adventure and you don't need a single note of reference to get everything the movie shows.
Now if you take Turning Red, yes, I think Kids will have a good time with it, the big red panda is fun to watch. At the same time, I can't see a kid or even a early teen getting the whole "memeber boy bands, member tamagotchi, member 90's anime, member what was like to be a child in the 2000's", and you can't separate that from the story because, well, that is the identity of the movie.
That's is why people said that Turning Red felt like a movie made for the director and her friends, because it zero in on her experiences that it dissasociates from the larger message of the movie about "being yourself", which on itself is so broad that you can attach to anything. It becomes less about "being yourself" and more "Being Domee Shi (the director)".
So a simple message that doesn't quite gel with a very specificy life experience based story, then you get a movie that feels like, for be better or worse, a vanity project.
Turning Red can be a fun insight of "what was like to be a kid on the 2000's", but ironicaly it has no interest in reaching out for kids right now.
What can I say, we are still living ãt the era of manchildren cinema.