Earlier quoted context omitted.
It's a somewhat blunt instrument used to internalize some externalities: Making a product and then destroying it is wasteful, and the market will fix all internalized costs of that waste, but some of those costs are externalized. Having society pay somewhat for producing clothes that are then worn, that's one thing. Having society pay for pointless waste is another. What you've said is: Looking only at the internaliz…
Again, the waste is not pointless, it's part of an inventory management strategy to ensure adequate supply. If your local grocery store established a policy that they'll never buy more meat than they're sure they can sell before the expiration date, they'd routinely run out.
The result of laws like this is not that the store will never buy too much, it’s that when they do buy too much they will give it away to somewhere it can be used instead of destroying it. It will not cost them much if any more to simply give things to food banks or charity shops.