Just compute the energy output of the Sun and claim they'll build a Dyson sphere around it.
Can charge a nice hefty subscription fee for using the Sun, just like Netflix.
> We believe the next paradigm shift for humanity is the creation of a resilient, perpetually expanding spacefaring civilization that drives continuous innovation across new frontiers, ultimately propelling us to Kardashev Type II status—a civilization that harnesses the full energy output of our Sun.
To be fair, he's not claiming here that SpaceX will accomplish this themselves, solo.
For example, I used to work for an insurance-related tech company. They claimed their TAM was $9T-- the value of the entire global insurance market.