The more experience you have sewing, the better you become at handling fabric. Maybe some kid from Sri Lanka can push a seam through faster, But the old tailor will make sure that the seam does not pucker.
I guess the whole question turns on whether it is hand-sewing by young people or machine-operation by young people. In the case of hand-sewing, isn't one of the plus points of a hand-sewn garment that it has that "human touch"? If someone is so accurate and precise in their sewing that the work looks
as if it were produced by a machine, such an aesthetic appeal is undermined. If I buy a suit with some nice topstitching done by hand, I expect each stitch to be ever-so-slightly different. In short: shaky hands = variation in stiches = more obviously hand-sewn = good. (I'm not advocating this view, just trying to report on what seems like a common intuition)