Is Kelly Slater the best Sportsman of all time?

At 50 years of age, Robert Kelly Slater is still on the world stage, competing in the elite WSL - World Surf League, and up until the last competition (in Brazil) where he pulled out due to injury, he was top 5 in the World.
kelly has won 11 World Titles - 1992, 1994, 1995, 1996, 1997, 1998, 2005, 2006, 2008, 2010, 2011.
He has won an unrivalled 56 Championship Tour Events - the most recent being at Pipeline earlier this year.
Away from competition, Kelly also owns the Kelly Slater Wave Co, an artificial wave in the desert of California (100miles from the ocean) where surfers can visit all year round and surf perfect waves. 
Even the WSL held events there for the Worlds best surfers. He has designs for more around the world - his second being constructed on the Sunshine Coast, Queensland.

References (Example)

[1] <name>, '<title>' (online, <year>) <link>.
[2] BULB, 'Write to Earn. Read to Earn' (online, 2022) <https://www.bulbapp.io/>