Then the question is really who is the most consistent athlete
Also gotta ask.....which sport is the hardest to maintain consistency over time?
Olympic sports require their own category because the time frame for peak performance is much shorter, particularly T & F, gymnastics etc. More leeway in sports like wrestling.
Boxing is tough. Getting hit in the face requires a different mindset. The more talented and successful you are, the more difficult it is to maintain the passion.
Of the Big 4, it's probably football....but there's probably more variance in football than other sports. You can have a lonnnnng azz career as a kicker, punter, QB etc., with a long peak....but you can also be done inside 3 years. Running backs fall off a cliff the fastest of any athlete in the Big 4. It's never gradual. They go from Pro Bowl/All Pro caliber to washed seemingly overnight.
Emmitt Smith is GOAT to me because most guys are completely done after just half the carries he had. Not even counting all the carries he had in the SEC at Florida and being that dude in high school.