I kind of hate these kind of debates because it's absolutely impossible to quantify. Football is the most popular sport in the world, it's also the most accessible, with the most availability in terms of clubs to sign for at a youth and professional level. How do you even begin to weigh up the difficulty of "making it" in that environment versus say the pressures of making it in an individual sport?
In my case, I played football and tennis to a pretty high level, and I found tennis to be far more competitive. One of my tennis teammates for example was an incredible player, ranked in the Top 20 in the country for his age group. Now consider that to even survive as a tennis player you probably need to be one of the 15 best players in your country at ANY age group. Basically you have to be one of the 15 best players from ages 18-35. If you're even the 10th best 19-year old in Britain, there's basically a 0% chance you're making it as a professional tennis player, now compare that to football?
How do you even compare football to American sports, where you can be the best player in the state at high school level, and you've probably only got like a 2% chance of making it as a professional player in the NFL or NBA?
And I'm not even saying he's wrong. Football is the most played sport in the world so therefore the best footballers are the best athletes in the world is probably a fine take, but it's not the "take" that he thinks it is. And it's this sort of dismissive attitude and his complete ignorance of basically any other sport that is quickly making me realise that Michael Cox is just a bit of an asshole.