I have had 0 and have about 30 flights. But I turn on airplane mode to make sure I am all good. Can't speak for everyone else though. But I am looking to get an iPad mini for this so I can have a larger screen.
Cellular on or off - it makes no difference to your flying.
That's just another unfounded superstition.
As for flyaways ... they are so rare for the P3 that they are more a myth than genuine.
Phantom 3s don't just fly away.
But operators that don't understand how they work often blame a "flyaway" for their operator error or misunderstanding.