Where are you basing these claims? I do pixel art, and dithering + anti-aliasing are one of the fundamental techniques in this medium. It’s widely-employed that there are so many beginner tutorials that teach these methods (I highly recommend MortMort’s channel, for example).

Also, I invite you to look at the Pixel Dailies twitter handle (and the #PixelDailies hashtag), you’ll see the works of several pixel artists and you’ll notice that dithering and anti-aliasing are common patterns.