No dummy, IF he had beaten Jones, Aspinall, and at least 3-4 others without losing, that's a 5-6 fights at a MINIMUM of 8 million/fight, which turns out to be a MINIMUM of 40-48 million. In that scenario he'd have made WAY MORE in MMA than boxing, AND had a mainstream legacy. Do you even math bro?
I'm not talking about this imaginary scenario, I'm actually using an all but guaranteed scenario to steelman your argument. I.e. if Francis played ball with UFC from the moment he became HW champion, 8 fights ago, plus the guaranteed 8 million against Jones. If anything, 20 million is a lowball of what he could have made.