Not sure about Elon Musk, but Apple comes across this way. They constantly talk about how they "reinvented" everything, "re-imagined" everything, "went back to the drawing board" etc while presenting new products. Kinda off-putting. But to be fair these people/companies do amazing work, so I guess some amount of ego is to be expected. Top athletes, musicians and pretty much top people from most industries have huge egos. Comes with the territory, I suppose.