What are the advantages of three phase induction motors over the other motors?

A Single phase induction motor includes a main winding, an auxiliary winding, a run capacitor, & a subsidiary star device. The auxiliary winding is configured such that the number of turns of the aauxiliary winding through which a current flows, varies according to the operating mode of motor. When the motor starts, the number of turns of the auxiliary winding through which a current flows is reduced there by increasing the start efficiency of the motor. when the motor runs in normal mode, the number of turns of auxiliary winding through which a current flows is increasing there by increasing the operations efficiency of motor