Yes! I remember thinking the same thing about those Skyrim loading screens: 'My GPU and monitor can output millions of colors, and my monitor only has about 2 million pixels. Why do these look so bad?[0]' I've always wondered if dithering would help, and how it would be implemented. [0] Bethesda's broken engine notwithstanding.
It's interesting how we thought banding was a solved problem back when we moved from 16-bit to 24-bit color. And it was, for a while!