Depends on what area of athleticism you are looking at. The best NFL players have the athleticism to be in the NBA if only they had the skills. Football is a lower skill level sport so you can def see some NBA players take on the NFL but only in certain positions, other places they would get eaten up.
NFL = Better body/muscle mass, less skill
NBA = More spread out athleticism and skill
Depends on what area of athleticism you are looking at. The best NFL players have the athleticism to be in the NBA if only they had the skills. Football is a lower skill level sport so you can def see some NBA players take on the NFL but only in certain positions, other places they would get eaten up.