Not to shill, but the reason modern razors make it harder to cut yourself is that the head pivots. This isn't intrinsically tied to being a disposable cartridge

Not to shill, but the reason modern razors make it harder to cut yourself is that the head pivots. This isn't intrinsically tied to being a disposable cartridge. I know that at least OneBlade and Leaf make razors with pivoting heads which accept either single-edge or halves of double-edged blades respectively. You get the benefits of lower waste/spend and fewer cuts/less careful shaving.