It's too early to judge. If he accomplishes his goal of establishing permanent and self-sustaining human settlements on other worlds then he may end up being the most important person ever, not just CEO.
His goals, at least, are ambitious in a way that those of the other people you mentioned aren't (except possibly Bezos, but Bezos doesn't laser focus on this stuff the same way Musk does).
There is no such thing as the most important person ever... all he did was fund some interesting ideas, which other people actually built. If we are going to single someone out for being the most important person ever, then that person would need to have some enormous achievement completed without the help of others.
His goals, at least, are ambitious in a way that those of the other people you mentioned aren't (except possibly Bezos, but Bezos doesn't laser focus on this stuff the same way Musk does).