[demosito666]

Probably not very hard, but it will cost 10x more than regular clothes. Current process is highly efficient and produces thousands of units per day with a dozen of low skilled workers. Whatever is not automated (and it's not much) benefits from dirt cheap labour in Bangladesh or Vietnam.

Your sewing robot will make a dozen of units per day and cost hundreds of thousands. Monthly salary of just several sw engineers from SV is probably greater than total operational expenses of a medium-sized factory in India for a year.