With today's technology it's really just a stunt, the resolution isn't there so it's no completion with traditional fabric.
With Shadowrun technology, where the forge has the resolution to build the tightests weaves there could be a lot of advantages. They kind of talk about this in terms of the bikini, you can control the structure of the fabric local so you would be able to control where creases go, how garments, sit as well as imbedding technology into the weave, adding things like zippers, snaps, plates all in one go.
In the cause of us bootlegging Zoe garments that are made from fabric, it would probably be more cost effective to use fabric rather than the forge IF we owned a automated garment fab. The forge is probably less efficient but the markup more than make up for it and, well, my character does own the forge.