I and a few others have a different view of chicken keeping to the majority.
The essential difference is I try to manage a chicken population rather than keep a few chickens. I want this population to be able to replace itself rather than go to the shops or hatcheries and replace those that die with yet another group of genetically challenged poor quality fowl. I keep a closed flock and I free range.
I want the chickens here to live as close to a natural existence as circumstances permit and I would rather not be burying them at 4 and 5 years old. I get attached to them.
Before the backyard chicken keeping craze took off in the USA most literature I read gave an average life expectancy of 10 years old for the heavier dual purpose breeds and 12 years old for the lighter bantam breeds. This is what I aim for. Next year I will have my first 10 year old Marans. My eldest bantam died at 9 years old earlier this year unfortunately.
Most of the local chicken keepers I know here expect their chickens to live to the above average ages if not culled, or predated. We don't have large commercial hatcheries or much in the way of keepers that describe themselves as breeders.
Many here start their flocks with an adult pair purchased form flocks with known heritage. Nobody here picks a few random chicks out a bin in the local farm store if they are serious about keeping chickens, or gets chicks delivered by mail unseen with no real knowledge of the quality of what they are getting. Some keepers here, particularly the game bird enthusiasts will travel to other countries to ensure they get quality birds.
That is very different from here, including me. I appreciate what you are doing and love hearing your stories. And I love having you comment and participate here. Frankly I would love to do the same but I do not have access to the land necessary.
Fluffy Butt Acres is a backyard pet operation. I want the girls to live as long as possible and be as happy as possible. I would like eggs but as they seem to have figured out right now, it is not required. I hope you are not offended by how I get my hens but that is what I have to work with right now.
And then we have people working at preserving rare and heritage breeds, people like me looking at it from a sustainable farming angle (aiming for a small profit as well as pets/food), and all our lovely Aussie friends

My first chickens came from a semi-local breeder in the form of a $380ish investment in eggs. I mostly was concentrating on Isbars (3H) Marans (2H,1R) And Barnvelder (1H,3R) I also got a few mixed breeds for Olive (1R) and blue eggs (1H,1R, but lost the hen to coccidiosis). That was out of 48 eggs, turns out hatching isn’t quite as easy as the hens and videos make it look! So I got some chicks LHxCCL (3H,7R) and 4 more Barnvelders (1H,3R) from a cancelled order the breeder had. They brought in coccidiosis

I can’t afford to be buying chicks/eggs to keep a productive and sustainable flock. Needing to grow my flock for egg sales, and to keep all those boys from going crazy, I needed more pullets. I’ve borrowed/rescued the chickens from the farm coop (11 Hyline, with all the reproductive issues, and 1 ancient Barred Rock). Then I figured “my pretty Olive egger boy might not give me eggs, but let’s see what we can do with his daughters before he goes to Freezer camp for being a jerk?” And thus my Easter-egger Marans/Ameraucana x Hyline Red mutts were born! 73 chickens under my care (and counting again come spring!).