Wait until you hear what happens when they lay their eggs.. Research from the University of Copenhagen found that around 85% of Danish laying hens suffer from keel bone fractures, which are caused by the internal pressure of laying disproportionately large eggs..

https://www.sciencedaily.com/releases/2021/09/210902124929.htm

The indigenous hen lays around 20 eggs a year, whereas a modern laying hen produces around 320 eggs a year. In other words, being a hen bred for the food industry is a full-time job. In fact, the egg laying appears to be such a strain on Danish as well as foreign hens that it results in bone fractures.

Yes.

Yes. A modern broiler chicken grows so large, so fast, if it were not slaughtered it would die anyway. Surely a cursed existence.

That is so bizarre. My dad's had chicken for as long as I've been alive, and doesn't slaughter them until much later and much bigger. I've never heard of them breaking their bones.

It probably depends on the variety, I know my dad is kind of into heirloom and older breeds so that's probably a factor.

Chickens have been bred to be meat bioreactors. but at that the meat is old and woody.