Helicopters don't just fall out of the sky, atleast not any different than planes fall out of the sky, they can auto-rotate to the ground without engine power.
You are absolutely correct about autorotation and helicopters not falling out of the sky. There is one nuance that the rotor blades still need to be able to rotate for this, and a failed gearbox can prevent that. Anecdotally that feels like the most common cause when I read about another crash in the North Sea.
True but even lowering collective and letting autorotation take over you still hit the ground REALLY hard - enough to sustain injuries to your back and neck in some cases.
Glide ratios in GA (like highwing cessnas) is much more forgiving assuming you can find a place to put down.
This future is already there:
We have flying cars: they are called "helicopters" (see also https://xkcd.com/1623/).