Back pockets need to be empty as you'll feel the pressure of anything in them after a while. Phone should remain in the vehicle.
Posted this on another forum, but applies here too. Direct response to your statement about phones. Your opinion about where one should keep their phone is just that, an opinion:
Last fall (2017) we had a baby in my wifes family that was born critically ill. My wife was a bit of a hot mess, and I was communicating with the father pretty regularly. If that makes me a sissy, well, whatever. FWIW, the baby passed away, he held on for 9 months. That was 9 months of being a sissy and trying to keep my wife on an even keel and trying to keep other peoples hopes and spirits up. My nose isn't buried in my phone while hunting, but it is on my person.
In response to the op, I keep my bib pockets empty, everything is my pack or in a hand muff.