Being proficient at FS does not mean you can fly a plane. Actually many FS actions are "bad training" for real life aviation. We take too many shortcuts. Which one of us always trims for each new situation? Who pays attention to mixture? RPM being too high all the time (or N1 settings for that matter)? Cabin pressure?
Even if you do all those things ALL the time though, you do not get the gravitational feel, if you will, of a real aircraft. The effect of thrust, drag, lift and gravity on your body and on the control surfaces.
Actually, I'm obssesive about those things. 🙄
But, the only time I'd attempt to fly a plane is if the flight crew were unable (Grade B movie).
If that were the case, I'd give it a try. I'd get someone t sit in the right seat and call out the airspeed so I could concentrate on keeping the correct side of the plane facing up. I'd squawk 7700 and try to get communications with someone who could point me away from populated areas.
If...I said if, I could stay airborn, I'd burn off as much fuel as possible and hope someone could guide me to where I didn't fly over zillions of people, to a runway.
Successfully landing? a 1000:1 shot. Still, it would be better than sitting with the passengers and screaming, "We're all gonna die!"