As for the map reading thing...
I was watching Aussie Gold Hunters a few nights ago and one of the prospectors wandered off in the bush without his walkie talkie or GPS. It took a while to find him. A map would have been completely useless because for many kms there were only tens of thousands of bushes, trees, and vast patches of dirt. No landmarks whatsoever.
I imagine that a GPS device could be more use than a map in many dense forests?
When I cycle somewhere new I have the route on my GPS, which does not have any mapping - I just follow a route line. I also put the route on my phone, which has all the OS maps for the UK on it. For me to get lost, either the GPS satellites would have to fail, or both of my devices simultaneously.
I have only had one GPS failure in 15 years, which was due to a rechargeable battery suddenly dying. It didn't run out of charge, it lost its ability to hold the charge it had been given a couple of hours earlier. Carrying a couple of spare AA batteries would deal with that issue.