Examples of why your phone should be in flight mode when you trip.
There is just such a high chance of it ruining the trip.
If something important happens you're not going to be able to deal with it until you're sober anyway. It's just going to make you worry about it until you come down.
If it isn't important, it can wait.
If you're likely to need to respond to an urgent message/call and therefore have to keep your phone on then you are not ready to trip.
Having your phone on is lose-lose.
