Comment by sien

Making these things make money is hard and it's really valuable. Without that people won't get to use them.

There is a list of defunct spaceflight companies :

https://en.wikipedia.org/wiki/Category:Defunct_spaceflight_c...

Here is a very small list of just a few of the defunct internet companies

https://en.wikipedia.org/wiki/Category:Defunct_online_compan...

It's also worth considering how many millionaires were made by the companies that the billionaires started.