If used for the final destination, then the address or POI coordinates returned by the search provider is closer to the alley than the street. Depending on the neighborhood and where visitors should be directed to get to your location, the private rd/alley may be appropriate or not.
In Chicago, the default is generally not. We've had someone recently jump from editing level 1 to 4 rather quickly seemingly doing nothing but activating alley turns. Alleys here are usually applicable for homeowners with garages, who already know the last few blocks to the destination.
I tell people using Waze to never count on the last few blocks; only that it might know more about traffic conditions and get them to an area faster. In the past 3 weeks, I've been misrouted to alleys for final destinations twice in Chicago.