> Yes but what I mentioned does not require any interaction, it still does change the route to a faster one without having to do anything. I don't see how that makes a difference in safety?

It makes a difference for people (like myself) who very much don't want the route to change automatically. It means that some attention has to be paid to the app so you can tap the screen in time to make it stop, and it means that you have a time-limited action that you must perform. Two things that add to the cognitive load and distraction.