This is because traditional film cameras had horrible images compared to what your eye can see. This resulted in various techniques such as movie make up and bright lighting.
Now that the camera is much better, all of those compensation techniques are now making the image look fake. The lighting is too bright, the makeup too heavy.
I'm not convinced that's the whole story. Even old movies converted to digital fall into the uncanny valley. Try watching bluray Godfather for example. Looks staged.
You might want to check the settings on your Blu-ray playback system, because the Godfather Blu-ray is one of the more "filmic" transfers I've seen, preserving the grain of the film print rather than attempting to "clean it up" with digital noise reduction, and it should play back at the original 24fps frame rate on any system that supports it.
Now that the camera is much better, all of those compensation techniques are now making the image look fake. The lighting is too bright, the makeup too heavy.