Cheap clothing is a civilizational achievement and good for human welfare.
So carbon emissions are bad, but then we should price carbon and not micromanage clothing inventory.
Getting common goods less expensive is good, making them too cheap is not. Imagine you are optimizing a math model, but nothing actually has prices. You just get a garbage point as optimum. You need to have scarcity, so that a system that optimizes the allocation of scarce goods actually works.
Clothing everyone is an achievement, but fast fashion is overshooting that target.
A bit like feeding everyone vs. having an obesity crisis.