@Gab1 , that's exceptional, especially for a RIR! My oldest hens have died at age nine, still pretty good.
I talked to a Cubalaya breeder who said many of his birds lived into their teens, and that makes them interesting, although I don't have any.
Mary
I value my older birds for the experience and flock management skills that they have, and especially any that are broody hens. Not everyone stays forever, but many do, and I have the space to take care of them.
If I wanted a commercial 'all in, all out' operation, it would be different. But...
Some stay for life, some die or are killed by predators, some are sold while still laying eggs, it just depends. Some go into the freezer too.
We all have the space we have, and need to manage our flocks so they are comfortable in that space. For me, that's 35 to 40 birds over the winter...