McGregor is one of the most lucrative athletes on the planet but there’s more to this story. He’s also arguably one of the biggest sellouts because everything changed after he fought Floyd Mayweather. The Irishman became a two-weight champion in the UFC but recognized his limited earning opportunities.
He somehow talked his way into a boxing match with Mayweather and convinced the world he had a chance. In the end, Mayweather dominated ‘Notorious’ but McGregor made an estimated $100 million. He was never the same MMA fighter after this because he no longer had the same extrinsic financial motivation (via Essentially Sports).