I'm sure we're already there with musicians as well. If you take Taylor Swift's annual revenue and multiply it by 5-10, you'll easily cross a billion. But she does require tons of staff for the stadium shows that provide the bulk of the revenue, etc. Not literally one person, but it's a company with a bus factor of one.

Lebron James reportedly signed a billion dollar lifetime deal with Nike.

And I'm willing to bet all that staff is contracted. Her personal employees (people she pays a regular fixed salary to) is probably in the single digits, or possibly even 0.