As someone who has backyard chickens and has tried raising meat chickens, they are pretty close with the current ones. Regular egg laying chickens don’t have a lot going on upstairs but you can still see them finding (relatively) creative ways to scavenge food and stay safe. Meat chickens just stand there. They can barely move or react to anything. One step above catatonic. They were treated well and given good living situations, but I had to put them out of their misery because they would overeat and had leg problems. It was spooky and sad at the same time.