You can indeed trade sample accuracy for sample rate as long as information is not lost -- and in dithering, information is preserved by diffusing the quantizat

You can indeed trade sample accuracy for sample rate as long as information is not lost -- and in dithering, information is preserved by diffusing the quantization error spatially. Look at the image you posted; on the right, the effective "pixels" have become larger while each has acquired more gray levels. That's a lower sample frequency traded for higher quantization resolution.