When used correctly, dithering can be a work of art itself. Pretty much all the artists I know who work on actual 8-bit platforms use both dithering and AA extensively, hardware permitting.
Example: https://csdb.dk/release/viewpic.php?id=149177&zoom=1
Anti-aliasing is used a fair bit in pixel art, but less so in artwork designed to look 8-bit. There weren't enough colors and palette space to anti-alias in older games, so it looks out of place when replicating the look.