I touched on this a little on another thread.
On our middle hunt (Cow in Medicine Bow N.F. WY-12) we came across a elderly hiker who had to leave his wife on the mountain in high-teen overnight temps. They had lost a trail then gone cross country for several hours.
He had a working high end working GPS.
He kept saying it was malfunctioning but he didn't know how to enter a waypoint or pull up the track log.
In our last hunt we encountered a hunter who was twisted around about 3 miles deep.
After our hunt we were told the story of a couple of folks who got lost and ended up crossing some private land to walk out.
The common thread is that the GPS stayed in the pack or the folks didn't know how to use them.
Gear is only as good as your ability to utilize that gear.
In the situation of the lost hiker; it could have been fatal.