You make a good case that his real contribution is merely writing checks to smart people. I would argue, however, that this doesn't need to come along with his baggage in terms of his distracting social media activities. It's pure self indulgence on his part, and likely making a lot of smart people not interested in his money regardless of how big the checks are.
If anything, Musk should focus entirely on the influencing and stop making decisions about product (see [1]) -- that is what he is good at!
[1] https://www.caranddriver.com/news/a15347233/musk-attributes-...