When the wheels of the moving vehicle are locked by brakes, the vehicle will begin to slip under kinetic or dynamic friction rates.
However, when the wheels not slipping and rolling during braking process the wheels will be acting to stop the vehicle through static friction.
Since the coefficient of static friction is higher than dynamic friction, the vehicle will stop faster when the wheels are not slipping.
ABS system allows the maximum static friction to stop the vehicle.
Simply put ABS brakes stops the car without slipping the wheels which actually provides quicker stopping. Since wheels are not locked and rolling it also provides direction control in other words keep the car in control.
Under ABS, one can apply maximum braking by constantly applying pressure on the brake pedal. The ABS computer will automatically regulate braking and prevent wheel slippage and get the shortest possible braking distance.
However, on Non-ABS, one must apply varying pedal force to get the shortest possible braking distance. Ideally, just when the wheel is about to skid one must reduce force on the pedal to prevent slippage. And then increase pedal force little more. This cycle is repeated quickly. This would involve considerable skill on the part of the driver.