These "visual joyrides" were never conceived and written as coherent movie. They are a collage of visual effects stitched together in post-production to create an illusion of story telling. Most of these "movies" go into production without a complete script, without a vision. What was shot "live" is re-arranged, mutilated and even re-created. The actors of sci-fi blockbusters are now in less scenes than their digital counterparts. As soon as the action kicks in, the sequence are 100% CG. Even in scene without big VFX, actors can be replaced. The (virtual) sets are also constantly changed for whatever reasons. If a desert in trendy, then it will be a desert, even if the shot took place in a city. Post-production will fix it. it's like magic!
Yes, it's a waste of money, yes it's a waste of time... But we are beyond sanity here.
I was once asked to work on a scene with a girl spilling coffee on her dress. For some strange reason it was not shot live. I was given only the action with an empty cup.
It took me a full week of hard work to do it. The fluid simulation was not that difficult, but the tracking was extremely complicated. The dress was made of a light fabric, constantly moving and twisting in all directions, ... I had to work frame by frame and even create a full CG actress to get some movements right. Why was it not shot live Why? I've spend about 50 hours on it, while it could have been done in 15 minutes on set...