It’s a tough problem because a screen simply can’t display the dynamic range that the eye can perceive. If the actual brightness values of the sky and scenery were mapped 1:1 to your screen, the display wouldn’t be usable at all. Either the sky would be all white, or the ground would just be black. And if all of those brightness values were compressed into a normal monitor color space such that the sky and ground are both always evenly bright, the game would look like a cartoon. It would look like FSX.
I think the simulator’s lighting model is really well done, and welcome its attempts at realism. There are indeed lots of times in real life when it’s really hard to see the ground when you’re flying because it’s too dark, and the sun’s glare makes flying difficult. It adds to the challenge and the realism. People sometimes plan their flights specifically because of the lighting conditions.
The simulator is emulating a camera more than it is emulating human vision. A suggestion for a wishlist thread would be to ask for the equivalent of a neutral density filter that you could add to the camera lens. Or even a polarized and tinted lens. A third party might be able to create this already by simply creating “add-on sunglasses” that sit in front of the sim camera. But I don’t think the base sim itself needs to be changed.