And what you will see in phone? just a point where you are in the middle of the forest. Orienteering maps are a lot more detailed maps that google maps, or another maps from phones.
You receive map with control points after your start, so you can't import it in phone before competition, to be helpful for you
They don't stop because they are reading the map and deciding where to go next while running. When they are running to one control point they already are deciding how they will run to next point, so when they are at the control point, they already have a full plan how to go to the next one.
Go to one competition, especially in Switzerland or Scandinavia, and you will see if it's "fake sport" or no, and you will see how hard is it and how much time you will lose to leaders