Noise reduction benefit is marginal. Most of the noise comes from tires rather than the engine. At 30 km/h tires are louder than the engine, so an EV driving at 50 km/h, which is the typical city speed limit, isn't any quieter than an ICE car.
A lot of jurisdictions have laws that say electric cars must emit thatbnoise while driving. Which is basically because you might not be able to hear them over the louder sound of gas cars. I hope that that requirement can go away if we get to near 100% electric.