Get lost, fall, and break an ankle …
OR just fall and break an ankle....
How long before anyone misses you and worries enough to call the Police?
No one knows you went hiking until they find your car at the trailhead.
You have no food.
You have no water.
You have no shelter from rain or wind.
You have no way to create a fire.
You don't have an adequate map.
You have a compass/light via the cell phone that both rely on a finite power source [battery].
You have clothes that may not be warm enough at night and, if it rains, that wet cotton is going to make it even more difficult to stay warm.
At that point, you are relying on getting cell phone service in the mountains.
Did you know that you should actually head up the ridge in this case rather than following a drainage to a stream and then downstream to civilization?
When you manage to get to the ridge, you may not have cell phone service.
Maybe Lassie will find her way home and tell Mom that Timmy is in trouble.
Now you may have done this hike and had a great day. But that does not make it a wise decision.
If the scenario I described unfolded, the hiking BBs would be having a field day discussing your choices.