Seems like the food producer would have a clear incentive to mark their products with sell by dates.

If I’m making a food product for sale at retail and I can mark it “sell by” some date, consumers get confused and think it’s no good after that date, the store that buys my food product will not want to keep it on the shelf because consumers won’t buy it.

The retailer has to discard the perfectly fine item and reorder from… me the food product producer and then I make more money.

I imagine the food retailers are happy about this and the food manufacturers are probably unhappy.