It wouldn't surprise me if the fast food industry in the US has basically driven the smaller producers out of business by giving the larger producers better efficiencies.
Part of that is probably that style of meat being regulated against. I don't personally eat meat, but I know that one of the concerns that people have with a potential US trade deal is the lowering of meat-safety standards.
We did a three week tour of the UK last August and cooked most meals... the cost of meat at chains like Tesco, Sainsburys, and Waitrose was comparable with US national chains, but the quality was far superior. As you point out, I didn't see any mega packs of cheap chicken breasts or pork ribs. I felt too like the quality of fruits and vegetables was on par with our high-end stores for prices similar to our "typical" stores.