He was a boxing fan, never a MMA fan.Well, he may have preferred Boxing to MMA, or Boxing Money to MMA, but after AJ khtfo does he still? Moreover is the money still there?
He got top level opponents, so he got top level money. I'd have to think the payday for Chisora for example would be considerably less.
If that was me, regardless of the money, I'd stay in boxing because that was the goal.
Plus your name is among the prestige of greatness in boxing. You can say you got in there with Fury and Joshua instead of Mirko Strips and Garret Hamburg or whoever the fuck is over there.