The product density actually changes the volume of powder, so whilst with water, a 20 mL tablespoon might equal 20 g of water, this is not the same for different powders. This powder is “fluffier” and therefore takes up more room by weight, so therefore less product by weight fits in a tablespoon. Think 1 tonne of bricks vs 1 tonne of feathers. Same weight, but far different volume.