There are always too many painful and different things to do in any business, so a single person will certainly start aggressively delegating and outsourcing after a few millions of income.

But not willing to grow over a 10 person team may be a strong and feasible personal preference.

My bet is on $10 billion with a team of 10 people.

Does that still count?

Instagram was bought for a billion dollars with a team of 13 people, so $10 billion with a team of 10 sounds possible.