I spent nearly two decades practicing magic in systems that rely on the actions of external entities to achieve results. Eventually I grew dissatisfied with the quality of results compared to the amount of materiel and ritual investment that were required. So I turned to Sorcery. I decided that I no longer needed or desired a middleman between me and the greater Universe.
Relying on one's own magical potential requires a different approach to doing magic than those systems that leverage more potent entities. The amount of gross potential magical capability that a single human being can muster is fairly minuscule. There is no Force Majeure in this arena. Therefore, a sorcerer must develop highly efficient methods of applying minimal force to achieve maximal results.
This is why my system advocates the concept of focusing intent on the smallest conceivable physical level of existence. Influence is used where it can cause a cascading effect of increasing scale until the desired results manifest at the perceivable world.