In children’s movies the antagonist/monster is often meant as a metaphor for the child’s lack of autonomy in an ambivalent world that they do not fully understand.
And then you have My Neighbor Totoro, where all the monsters are friends, and the bad guy is just chronic illness, children who have let their imaginations run wild and fear the worst, a sibling getting lost, and at the end basically nothing happens which is the best news considering. There is no metaphor for human struggle, it’s just human struggle.
While some of his movies like Castle In the Sky, Mononoke and Nausicaä follow a modified Hollywood bad guy arc (in Castle half the bad guys practically become chosen family, in Spirited Away they become allies), a lot don’t. Up on Poppy Hill is essentially two teenagers in love discovering to their horror that they are first cousins, despair, and then discover that one of them was adopted.
But in all of them is the self-rescuing princess. The child either has to save themselves or at least demand the help that they are rightfully entitled to.
I got to introduce some kids to Ghibli right as Disney started distributing them. If you’ve seen Lasseter’s introduction to Spirited Away that’s where we were at that time - I’m telling you a secret that should not be a secret. And they in turn “forced” their friends to watch them in the same way my generation forced people to watch The Princess Bride; like it was a moral imperative to postpone other plans and rectify this egregious oversight in their education.
To me Ghibli often seems closer to the medieval / early modern narrative of the knight's adventure, which is a variant of the classical Western arc (initial stable situation, incident, helping figure, self-doscovery, resolution), even without considering the "Princess in the Castle" aspect (which can also be considered the female narrative counterpart).
My kids (8 and 6) snuck out of bed and ended up watching Grave of the Fireflies with me. I originally didn't watch it with them because of the subtitles, but they were hooked.
I'll be the guy to mention Grave of the Fireflies, which is also Ghibli, and which is the Totoro flipside as another, "There is no metaphor for human struggle, it’s just human struggle," situation. In fact, IIRC, they were released as a double feature (imagine being in THAT theater). As with Totoro's joy, GotF's devastation lies in its lack of concern for fitting events to any overarching metaphor. People make choices and there are consequences. That's all. The story ends when the viewpoint characters have nothing else to say.
It’s a standard trope in a mahou shoujo anime such as Sailor Moon or Futari wa Precure that the enemy tries to infiltrate the hero group and ultimately gets domesticated by Japanese society. I think of how the antagonist joins the party in Tales of Symphonia as a playable character.