I think the problem here is that there's a distinction between "pixel art" and "art created observing obsolete technical limitations". Additionally, just becaus

I think the problem here is that there's a distinction between "pixel art" and "art created observing obsolete technical limitations". Additionally, just because a piece of art is technically impressive, doesn't mean people should find it artistically impressive. When we only had 16 colours, it was harder to make great-looking art, but that difficulty didn't make the art look better. The essence of pixel art is that (it seems that) every pixel is placed with care. An image which uses 45 colours but looks like a dithered version of a full-colour image does not look like every pixel is placed with care. Quite the opposite: it looks like the image you're looking at isn't even the image the artist wanted you to see. Hyper Light Drifter has great "pixel art", but couldn't have been achieved on a 16-bit display (without either noticeable banding or dithering). But, the way it uses colour is clearly inspired by great 4-bit artistry. Although there are many more than 16 colors, neighbouring hues are contrasting, blending is used to indicate glows or shadows, and blurring is used to indicate depth.