No matter how slick the demo is in rehearsal, when you do it in front of a live audience the probability of a flawless presentation is inversely proportional to the number of people watching, raised to the power of the amount of money involved.
Even if I had $200 million, I’m very wary of overusing CGI. I think it’s a great tool and it can be used really effectively, but I feel like it does tend to be overused and especially in sci-fi stuff.