Durable, nationwide discounts on low-margin, premium products aren't a norm in the grocery industry. It would be similarly noteworthy if Kroger started selling dry-aged prime ribeyes at $8/#. (Less so if Costco did it, but Costco isn't a normal grocer).
Two minutes of searching tells me differently. Grocery stores have used loss leaders for decades to get people in the store. Why do you say the opposite?
Loss leaders aren't new, but usually they are either temporary, local, or on low-value products (think oranges, chips or soda instead of salmon)- or all three.
Even Costco's prime ribeye bulk packages don't turn out to be loss-leaders, despite widespread belief to the contrary. Here, the evidence suggests that Whole Foods halibut is in fact a nationwide loss leader.
Kroger (Ralphs, etc.) sometimes sells grass-finished prime ribeye at $8/lb...as a loss leader to get people to buy the high-margin condiments, etc. they would eat alongside the meat. The sales only usually last a day or until supplies run out, but it does a pretty good job of bringing the keto crowd in.
