All of these Musk lead 'X' companies, buy each other, invest in each other, then sell each other to each other, and re-buy. Are we sure this isn't some Ponzi s

All of these Musk lead 'X' companies, buy each other, invest in each other, then sell each other to each other, and re-buy. Are we sure this isn't some Ponzi skeem? Is Musk just using purchasing of his own companies as way to inflate them?