> You're in the middle of nowhere with, presumably, people you trust, and if you're intelligent, you're armed and observant, so what's the issue in those use cases?

In what case would I pull out my smartphone to speak with people within 100 feet of me though? I've never hiked with people far enough apart that we can't shout to each-other.

Still more private and secure to not have the smartphone on me at all.