This thread is getting weird, but wanted to try and answer it in a real way
If you go back to the historical definition of athleticism, one could say the decathlon epitomizes the perfect athlete. Speed, strength, jumping, throwing, etc.
For basketball, obviously everyone is an athlete.
Some players rely more on skill. When people say athletic in basketball, I think it is implied they are really saying "raw" athleticism. So the attributes mentioned above.
And a good basketball player will have a mix of both skill and raw athleticism. If you think of the best of the best - Lebron, Jordan, etc - they have tons of both parts. Guys like Giannis start more raw than define the skills. Plenty of guys who start as good shooters need to bust their butts to remain relevant in the NBA, and keep up with the good athletes