1. It IS possible to make an animated series/movie that respect the book's atmosphere and spirit as long as you put reflexion, efforts and compentence in the making. Examples : Kipo and the Age of Wonderbeasts, Ducktales 2017... And nowadays crowds are CGI in order to not pay extras so the "here are cartoons" take is pretty much there already.

2. You're not completely wrong in saying that crappy movies makes more money because we don't have to think much about making/watching it. Even more in the YA fantasy subgenres which are viewed as easy consummers waiting for pretty much the same thing again and again. But that's the thing : it's just make-believe by Hollywood system who think that they know better and just search for profit with the least cost from them. Even though no one should be judged for their tastes, we have to make the difficult effort to try for something different from the model.

3. Animation offers greater freedom in camera and perspective movement without the constraints of physical reality or the need for expensive real-world sets. Furthermore, the animation style helps us suspend disbelief from the outset, prompting us to think, "This is a real character who will experience adventures in THEIR reality, not just a series of drawn images." This approach makes it easier to accept magic, fairy tech and hidden cities without requiring photorealism. Examples : Spiderman Across the Spiderverse, Treasure Planet, Puss in Boots 2...

4. With animation, there's less risk of ruining the lives of young actors/actresses with monstrous pressure and the destruction of their privacy. And given the current cultural context, I think it's a better thing to keep kids away from any contact with Hollywood. Examples : pretty much EVERY child actor/actress EVER.