It's not really a matter of relying on a cell phone. A smart phone is a multi-purpose toolbox and it can come in handy if you have the rights tools in it. I leave mine off unless I am using it, which is rare, so I don't have any issue with batteries going dead.

If you do break your leg on a ridge where you have a signal it'd be nice to be able to communicate with the world. You can if you have your phone, you can't if you don't. It's that simple.

I understand that there are still great expanses out West where there is no coverage, and probably never will be, but that's not the case when you get east of the Central Rockies. As a general guideline I think it's time to stop promoting the idea that cell phones are not worth the weight.

I don't think it's ready to be promoted to "Essential" yet, but it should be a weighted decision based more on usability in the area you'll be backpacking than just personal preference.

It's not just your life you could save if you have a cell phone with you.