The problem with these things is that they are massive projects with no financial benefit while costing a lot to even run, let alone build. The reason most people are not driving electric cars (including me) is because an internal combustion car is cheaper over the cars whole lifecycle.
This is why I don't have an electric car, well truck, right now. The entry price for a manufactured car is just very high even if the operational costs are lower. It isn't like I wouldn't want to have one as I've been interested since the 1980's. I even considered doing a DIY truck back in the 1980's. The problem back then was more about the batteries than anything making a lead acid powered truck basically a summer car.
However I really see the equations turning in favor of electric products pretty rapidly. If Tesla is successful with its "pickup" (really an SUV in my opinion) it will be very cost competitive. In part that is due to Detroit grossly over charging for the pickup line. But Tesla has certainly attacked the maneuverability problem from many directions which should change the electric cost structure over the next 2-3 years.
Well at least that is my hope; Tesla selling every car they make, months ahead of time, doesn't give them a lot of incentive to lower prices. In any event an affordable electric automobile has been a life long dream. The surprise is with retirement not far away at all it looks like this could be real and cost effective.
Musk has already made SpaceX turn profits on this whole rocketry shenanigans. There are costumers that pay big money to get there commercial satellite up there into orbit, or to deliver stuff to the space station. The reason they pick SpaceX to do it is because they developed the latest in rocket technology to make it more cost effective. They also use this new capability by launching a better satellite internet service called Starlink.
Musk certainly has upset the world with just about every company he has his fingers in.
So they keep developing there rocket tech to also become the first commercial provider of interplanetary transport, and the most attractive first step is Mars.
Musk's hope is for humanity to escape an extinction event on earth. It is actually a good idea considering there is nothing we could do to survive some of the potential extinction events that could happen. In this regard he is no delusional at all.
However establishing humanity on Mars will not be anywhere near as simple as he thinks. does that mean he is delusional? I can't really say but I do know that having all your eggs in one basket is never a good thing. Sadly a lot of people will likely die on Mars before we have a self sustaining settlement. From what I've seen he is not even delusional about that.
It's only governments that can launch and run a non profitable project that benefits humankind as a whole. Commercial companies can't do that because they would eventually run out of money, at what point the banks stop giving paychecks to the people that work there and those people stop working for you.
I would also say it is almost impossible for government to find a non profitable project that they can invest in an not screw up. About the only one we can really say was such a project was the Apollo program. I'd also have to say the Manhattan project similarly benefited humans as it made contemplation of nuclear war pretty horrible for most of the big actors. Sadly we now have far too many sub standard governments, run by the mentally ill, that don't see nuclear war as evil.