Conor McGregor
It may feel dumb to say that McGregor destroyed his career. He’s one of the world’s wealthiest athletes in the world and won two titles with the UFC. Meanwhile, he earned a fortune through his whiskey business and other outlets. But his partying cost him dearly over the years. This is true in terms of his bank balance and his legacy.
The Irishman has had more nights in jail than fights over the past few years. He infamously creates havoc wherever he goes and has a few drinks or sniffs cocaine. McGregor destroys phones, hits old men, and allegedly has intimate relations with random women along the way (via The Mirror).