Many more billions have been spent by others trying to do these things and they have failed.
Is that supposed to discredit him? He started with nothing. Nor is simply having money anywhere near a guarantee of success in that industry.
Nothing but a very comfortable safety net. I mean come on, his parents were part of the group of people who fled South Africa after the end of Apartheid... not exactly rags to riches.
He's done a lot, but "started with nothing" is seriously disingenuous. Additionally: you don't have to "start from nothing" for your achievements to be worthy.
If you were born in a first world developed nation and grew up above the poverty line in your area, you are not a rags to riches story.