I won't contribute because speech interfaces are imo terrible and against the proliferation of Echo and Duplex like services, but the data collected is listed here
speech interfaces are developed by large corporations and there is nothing you can do about that. With Common Voice you are helping to create open-source alternative, which is a positive thing, I guess
Speech interfaces have some limited usecases where they are much better than alternatives. For example in situations where you need your hands for something else, like in a car.