Here's the thing: The BFG should be great. Spielberg directing Roald Dahl with a hefty budget and gorgeous visuals? Sign me up! But the reality is that this movie just doesn't land for most modern kids.
The pacing is glacial, the runtime feels endless, and while the imaginative elements are there, they're buried under a film that takes itself a bit too seriously. The scary giants are genuinely frightening (which isn't bad!), but the quieter moments drag. That 57% audience score versus 74% critic score tells you everything—adults appreciate the craft, kids check their phones.
If you have a patient kid who loves Roald Dahl books and can handle some legitimate scares, give it a shot. But don't be surprised if they ask to turn it off halfway through. The book might honestly be a better bet.