That’s very true! Today we don’t measure either breast in much detail, so only custom makers account for differences between left and right. I’ve seen a few bra-makers adjust for asymmetry in both the positioning of the breast on the chest wall and the shape of each individual breast.
Fun historical note: “right” and “left” shoes were a recent invention. Prior to mass manufacturing, many cobblers produced one type of shoe for both feet! It seems strange to even consider that today, and maybe one day we’ll reach that for breasts, too.
I wonder if some with asymmetry will prefer to look asymmetrical, in addition to those who want to even it out!