There's a lot of hair splitting going on, but I think the bottom line is it looks bad. Whether it's the cinematography & lighting, or the physical production design, or the CG augmentation, or a combination of all, this is not a visually-successful first trailer. The design looks weightless, the contrast is low, there's a shiny artificiality, and to me it looks quite obvious where the physical set ends and the greenscreen begins.
It's a growing problem in Hollywood, not exclusive to WICKED. A production can still build massive sets while also using a ton of greenscreen (FANTASTIC BEASTS and LITTLE MERMAID, for example). And smaller-scale period pieces can still look terrible (GILDED AGE and COLOR PURPLE, for example). Marvel has a big VFX problem, and there are a lot of awful-looking streaming blockbusters.
It becomes especially frustrating when we have had a number of really beautiful-looking blockbusters of late (the recent Hunger Games reboot, Avatar, Dune, Oppenheimer, Top Gun Maverick, Barbie, Indiana Jones, the international sensation Godzilla Minus One, etc).