If your investment plan is to follow the saying of a person who has billions of dollars, and there are more than a million people who follow his accounts, then it is likely that you will buy with the rise of the wave and you will achieve losses due to the emotional and ill-conceived investment.
Elon Musk is one of the most personalities that changes a lot of his views and convictions, as he can do something and reverse it within a week, and therefore he is not the ideal person who enables you to make profits. If this is your only investment plan, then the best for you is to start DCA.
Truly, billionaires and influential people like Elon Musk, can manoeuvre any system to their advantage, as long as it favours them, not minding millions of people their actions might disadvantage. So I agree that this set of people might not be the ideal role models to copy, because even if one of their investments or utterances brings a lose to them, it won't affect them, but the same thing can send another person who does not have their financial strength to poverty.