Your friend's experience sounds terrifying. Luckily, my city is safe for the most part but I will definitely keep that in mind. I plan on having a camera mounted to my helmet to record everything just in case something happens.In my opinion it it isn't worth it but I'm only saying that because one of my friends had a very scary experience not too long ago doing just that.
He was doing Uber Eats in a pretty bad area (his fault) known for gang violence and carjackings. He has his phone on his Ram mount on his handlebars, couple of dudes came up to him pushed him off his bike and took his phone. We all told him he's super lucky they didn't take off with his bike as well.
Carrying food isn't really a problem, I have a pretty good backpack that I have been using for some time now. The only problem really is drinks. It's quite difficult to carry them unless you have saddle bags or something that is able to hold them good. I have been able to pull off carrying them in a pouch in my backpack zipped up both ways so that there is no room for the drink to move.