Yeah, the landscapes look nice. And of course stories are a pivotal element. But watching a play that has terrible sets and costuming is extremely distracting, even if the actors play well and the story is sound.
My biggest design complaints are with the characters, they just look like toys for very young children. Their costumes are like some child’s idea of proper gear, and their faces and expressions are more simplified than those in even the first episodes of CW. As for the animation quality, while this team isn’t the same, technology and technique in the industry in general has improved since CW. Budget differences are more of a legitimate issue, but that should only affect character or set execution, not the designs themselves.
Presumably the original CW series were marketed to include children as well, but their environments were still more realistic, and weren’t trying to make every texture, color, contour, and light source in the frame unmistakably soft and friendly.
I don’t deny there is work and complexity in the design or the stories of Rebels. Anyway, I’ve only seen screenshots and clips, so I don’t have a basis to discuss it extensively yet.