The major advantage of using this foundation is the strength that it provides irrespective of the soil type. Concrete attains strength with time, thus this foundation gets stronger along with its age.
It evenly distributes the loads, that are getting applied to the ground floor, to the footings, and further to the subsoil. This avoided concentrated loads, and by uniformly distributing the loads, it protects the soils from sheer failure.
Concrete is the most common construction material nowadays. The reason for that is the strength it provides, regarding the low cost of the material. Also, due to being a very common material, the repair techniques available for concrete are widespread, which allows not to repair of any sudden defects in the foundation, but also to attain its previous strength.