To add to the possible justifications for this project, the YouTube channel Economics Explained made a nice video on how these insane megaprojects can make sens

To add to the possible justifications for this project, the YouTube channel Economics Explained made a nice video on how these insane megaprojects can make sense. Essentially, they are meant to be long and expensive just to attract enough foreign companies to establish permanent presence in the country. Once that happens, the idea is that they eventually start to contribute to the SA economy independently, helping them move on from oil only economy. It makes sense if you consider that when you have oil, it will make your currency strong, so exporting goods is expensive and that makes developing other industry difficult. Also, investments, people and other resources in your country will be all mainly directed towards oil, since that's where the profits are largest. So to escape this trap, you have to basically do something rather crazy.