My broody stopped laying for one. I let her be broody for a bit in hopes it might sort itself out. Like you, I didn't understand why people went through the trouble of breaking a broody, why not just let hormones run their course? Then there began to be problems. Something changed in her demeanor and it totally disrupted the pecking order and there were daily fights. My previously peaceful flock had peck wounds, I'd find blood on the waterer, there would be feathers about, I'd see hens flying through the air with hackles raised and hear noises I'd never heard. So one broody managed to disrupt the order of things and there was pecking and fighting where there never had been before. Now that she's no longer broody, things have returned to normal as if it never happened.