Soccer is number one around the club, becuase it was the earliest form of football, spread through Europe and then their Colonies. It's the number one sport in many countries. Its also conceptually easy to play, and easy to have a pick-up game. All you need is a ball, some space, and a basic ability to kick.
Basketball continues to gain popularity due to lack of space. In many large cities, and in the densely populated countries, people have no yards, limited access to parks, and even schools are often hi-rises. A hoop can be slung up just about anywhere, and even a full court is a relatively small footprint. Plus you can set up a court in multipurpose hall, that is used for assemblies, gymnastics, dancing, tennis, etc, etc. Plus the relative speed of a game makes it easier to schedule multiple games when running a league.
In Australia we mostly all grew up with yards, large parks are ubiquitous, and schools have massive ovals and outdoor areas. Hence for us, basketball is a choice from a wide range of options.