He already has a fantastic proof of concept. Sure, it will take a little longer, but he can easily raise the billions in funding and find the people to build it.
Because it will cost billions to build and run and the builders have no clue how to get the money, and once they have something built, how to keep the money flowing in.
Like how Steve Jobs invented computers and the iPhone, this entire rotten American tech culture of effective altruists and randian freaks, it's one big cult. That's why it looks so freakish from the outside, it's end stage hyper capitalism.