It's actually because it's a loss leader. Most consumers aren't just going to buy a turkey. They're getting all of those other fixins that go with it, and those prices are pretty minimal and steady no matter the store. Even cheaper by the pound, it's probably gonna be the most expensive thing you buy for a Thanksgiving meal. But most people are going to need one. People know all of this, so they shop for the best deal on turkey. That gets them in the door and since they're already buying, they go ahead and buy all the other things they need to prepare. They almost definitely lose money on those turkeys by themselves but make more money overall by selling them cheap. And for chain stores, the individual store isn't eating those costs. Those losses get written off and corporate eats the loss.

And sure, there are better quality turkeys, but you're gonna pay through the ass because those farms aren't producing at the same scale and can't sell to the stores for less, and there definitely wouldn't be enough to go around for all the people buying turkey every year. But if more people buy from those small farms, they can't upscale that same process to cover all those turkeys, so they'll resort to factory farming as well to keep up with the demand. It's very much a similar problem as complaining about traffic when you are also traffic. The only solution is to opt out but we live in a society and opting out can have consequences.