Building a demo for this would be challenging, but come on. They have been at this for what... five years now, and had $2 billion to work with?

Besides, hype can be very dangerous. Look at what happened with No Man's Sky. They rode the hype train to the Moon and came crashing down hard because the product utterly failed to meet expectations. That's why it's important to temper hype with regularly administered doses of realism.