Think about how much your phone cost. Would you leave that amount of cash unattended. A new model I phone is expensive. Also what about photos you have on there, willing to lose them? What about bank cards, store cards etc. what about all the hassle sorting it all out. I know that’s why lots of people leave their phone in the cabin. I always used to, but it is now very handy to have with me. ( my preference). I use a small cross body bag, just big enough for my phone and a tissue!