Camera bags are pesky things. It’s hard to spot their inadequacies until you use them in anger. And they can get expensive. You can end up buying several before you hone in on something that works for you.
I’m as capable as the next person of making a stupid decision when I’m out trekking, so I hedge my bets by being in the habit of carrying some safety kit. This kit can be the difference between having a good trip and something that is quite unpleasant.