Bit off topic but yes, that’s something that always makes me think. When I was flying GA IRL 10,000 ft was an absolute maximum, regardless of whatever the aircraft was capable of, without supplementary oxygen.
But in the sim you can fly as high as you like without any effect - I’ve overflown Mount Everest in the turbo Bonanza!
Perhaps a third party dev could make something that simulates disorientation - although I’ve never been there I think the sim will actually create a “grey-out” if too much G force is experienced by the pilot.