#3. Former World Champion Mark Henry quietly walked away in January 2021
Mark Henry first appeared for WWE in 1996 and went on to become one of the company's most recognizable stars in the two decades that followed.
From the Nation of Domination to Sexual Chocolate and then World Heavyweight Champion, "The World's Strongest Man" accomplished just about everything whilst under contract and opted to retire from the business in 2018.
Following WrestleMania 33, Henry transitioned into a role backstage and was the man behind Bianca Belair and Braun Strowman's career switches.
Interestingly, Henry came out of retirement to compete at The Greatest Royal Rumble. After an appearance on RAW in January 2021, he walked away from the company.
It wasn't announced that the WWE Hall of Famer had left and it only became official when it was revealed that Henry was All Elite in May of that year.
Henry was unveiled by AEW at Double or Nothing and has since become part of their commentary team on Rampage as well as working as a coach.