Why does Hawthorne describe the stitching on the fabric as a "forgotten art"?

The art of embroidery is in a class all its own.... most of the intricate stiches were time consuming and difficult. Over the years, the art has become a thing of the past. Today, it is almost nonexistent..... replaced by technology that will never be able to reproduce it.

It had been wrought, as was easy to perceive, with wonderful skill of needlework; and the stitch (as I am assured by ladies conversant with such mysteries) gives evidence of a now forgotten art, not to be discovered even by the process of picking out the threads.