This photo is soo weird. As if Pied beau stands on the head of Merle.
I haven’t got a clue. I don’t believe any records are kept of backyard hobby chickens.
I know that the persons who who sell sexed chicks and pullets are not so nice for their chickens. The chickens, kept for sale and for breed contests, are often kept in small cages/runs. The ones who try to make a profit can’t keep the oldies.
The contest / show breeders have limited space and can only keep the ones good enough for their breeding program.
In general the surplus cockerels get eaten and old hens are good for a soup.
The ones who keep the chickens not just for eggs but also for company or pets often choose to give the chickens a long life.