Weight is an important factor for us too. The thing is, since this is a leather case, the nature of the material governs us - especially so with full-grain leather which can be rather "thick". Our hides are chrome-tanned which enables them to be a little thinner & softer than veg-tanned leather.
Apple's leather case from the 12 series onwards seem to use an extremely thin hide (possibly heavily sanded down for "uniformity"), and we can understand why Apple does this since a lot of their customers chase perfection with their products, and the natural grain pattern of full-grain leather might be perceived as "defects".
While there are ways to make the case lighter by using a kevlar core structure, this would make the case prohibitively expensive with minimal weight loss. Another 3-5 grams can be saved if we swap out metal hardware for plastic ones.
With leather, it's pretty much a tradeoff. Weight comes with the material. Same reason why track-focused versions of road cars strip away leather in favour of Alcantara.