Your measure of market share is a reasonable one, as are the two I proposed being profit and creating and succeeding in entirely new markets.
They are new markets too, it's not rockets, it's reusable rockets at incredibly lower cost to orbit and new capacities to previous ones, it's space based communication networks that are again a serious generational leap ahead of whatever was before, it's the emergence of a serious replacement for ICE vehicles. In all these markets, his companies are the only market share! He owns these markets, because he created them, and is multiple years ahead of the rest of the world's highly motivated competitors.
I'm not detracting from the successes of the other guys you mentioned. But Musk can very reasonably be called the world's most successful businessman at the moment on multiple metrics.
It might be a competition between Musk and others, but it's the opposite utterly inept, which was the point - trying to give the benefit of the doubt to the OP per HN guidelines, while also keeping the discussion grounded in rational sanity.