What is the importance of slip in a 3-phase induction motor?

Slip creates a relative speed between the RMF and rotor. That keeps a torque continuously acting on it when the motor is running.
So what would happen if slip becomes zero?
Bcoz there will be no relative speed between RMF and rotor, and which will stop inducing rotor current. This will stop the production of rotor flux, thus no torque will be generated. As a result, the rotor will cease to rotate in the absence of running torque.