technology / D2C / supply chain startups are desperately needed in this area to solve these problems.
At unspuntech.com (where i'm employed) we're working on creating high quality denim garments using 3D body scanning as the basis for custom fit. This allows us to go 0 inventory, and consumers generally don't mind a 2-3 week wait time for manufacturing thus far. up to 10-30% of garments end up unsold, so 0 inventory can have a large effect. We're also working on robotics solutions to remove steps from the manufacturing process, and eventually to reuse parts of the garment that get worn out.
More thought has to be put into the fast fashion part of the equation -- consumers (moreso women than men for clothing) want a large variety of options, and if they can get them at the cheapest prices, why not? There either needs to be a shift culturally (maybe look at how organic foods became prevalent at super markets) or through some sort of regulation (not ideal).
if any hner's want to talk more about these issues, please email me!