Like, are eg. Musk and Zuckerberg doing this for bragging rights about a number on financial statements?
To be honest I have no idea about Zuckerberg's motivations. With the proposed billionaire tax in California, recent reporting indicates his main concern is retaining voting rights at Meta.
With Musk I believe he is investing into space flight and colonizing Mars.
I fundamentally don't agree with the idea that rich people are evil and motivated by nothing other than greed.