I don’t think that solves the issue they want to fix. The issue is brands that are stylish destroying clothing that’s now out of style (preserving brand value).

The price point is already high enough that taxing raw materials doesn’t really push the needle on price, they’ll just pass the costs on.

Utilitarian brands already don’t want to destroy clothing because their customers are price sensitive.

This forces the brands to do something with excess clothing. I suspect they’ll do whatever is the closest to destroying the clothing, like recycling them into rags or shredding them for dog bed filler or something. Maybe even just recycling them back to raw fibers.

How recycling by shredding is not destroying?

If the regulation specifically prohibits burning, it makes sense, as a measure to limit unproductive CO₂ emissions.

i would think chanel quilts would sell very well

But what do you do with unsold Chanel quilts?

Turn them into insulation! This is what happens with old denim jeans: https://www.henry.com/residential/products/insulation/denim-...

Chanel; the ultimate luxury insulation.

Cut the price, this is basic microeconomics.

That is not what they should do according to microeconomics because luxury goods are Veblen goods. Decreasing price would lower demand, at least until they lowered it enough that it was no longer a Veblen good.

Basic microeconomics is just that: basic and thus an oversimplification.