Apple uses clock cycles very efficiently, and everything is tightly integrated to maximize that efficiency. Android handsets use the brute force of more RAM and faster processors to achieve similar results, without the efficiency. This is why Apple handsets meet or even beat Android flagships at many tasks, despite having less RAM and slower-clocked processors with fewer cores. It's also why Apple handsets can last all day on a much smaller battery than a flagship Android device. At the risk of stating the obvious, clock cycles use energy.