Why isn’t this possible with current technology?
Today, garments are usually sewn together piece by piece using the same cut and sew technology of the past century.
Take a sweater for instance. The torso, the neck, and the sleeves are all individually sewn and then stitched together a la Frankenstein. This is why most garments you own have stitching along the shoulders, down the sides, and around the neckline.
“Why is that bad?”, you might ask. Well, for one, it creates itchy stitching and inconsistency in sizing for consumers. For another, the multiple stages of cutting, sizing, and sewing creates substantial waste.
Finally, it forces the reality that the materials and labor for traditional cut and sew manufacturing need to remain inexpensive to keep consumer costs low. If so much material and time are wasted in this multi-step process, these inefficiencies need to be offset by cheap materials, cheap labor, and high product turnover.