When you are on a tour and you want to find a restaurant, a store, or an attraction:
With the Garmin cycling specific units, you can use your phone to search online for whatever location you need, and then immediately send that over Bluetooth to the GPS unit, which will then give you turn by turn callouts to get you there, including getting you back on track should you miss a turn. If you prefer to design your own route to the location instead of rely on the unit's built in routing, you can draw a route using whatever phone map app you prefer, and then similarly send that route to the GPS via Bluetooth.
It is incredibly handy for touring.
Thanks.
In the past I have found the Open Street maps list of businesses or whatever to be adequate for locating that sort of thing on my GPS when I load a map at home shortly before my trip so that the maps have the most up to date list.
But I can see where it could come in handy if you do not update your maps before a trip.