I think you're right in that this won't have much immediate impact on the service providers.

But think of this as a step towards commoditization of services. It's a small step from "Hey Siri, get me an Uber" to "Hey Siri get me a ride", whereupon an Apple bidding algorithm gets you an Uber, a Lyft, a GrabCar, etc. based on e.g. price, wait time, and reviews. As a user, I wouldn't necessarily care which platform got used as long as it meets my need.