A number of GPS navigation apps run in the background for a good reason. When arriving at a destination, you can quit the app. While such an app is running, the location services icon will be available in the status bar as a reminder for one.
A music streaming app will be playing music in the background, which you can hear. If you no longer want to hear the music streaming in the background, quit the app.
Very few apps, and based on the total number of apps available is just a handful that run in the background since there is no reason or benefit for the overwhelming majority of apps to do so. A GPS navigation app running in the background allows for performing other functions while the app is running so your location is not lost and if a turn needs to be made you can still hear it. GPS navigation apps take longer than a fraction of a second to get GPS acquisition again from a cold start. And when such an app is being used, it is while in a vehicle where a vehicle charger can be used.
A music steaming app should be self explanatory.