As far as I can tell, most here do not cull at all and keep their hens as pets as they get older. That is fine, but I consider my chickens as livestock. I do cull at their 4th winter as I've observed chickens having a small decline in egg production in their 3rd year and a very noticeable decline in their 4th. I've seen older chickens suffer with various maladies and I'd rather give them a good life and quickly harvest while they are still healthy.
I have come to learn that my chickens do not lay enough eggs their third winter to justify keeping them. My plan is to now harvest them before their third winter. Which means I am getting new chicks every other year.
I think where you live makes a big difference as well. I live in northern Minnesota and for the next week we will have temps down to -24F at night. That's just hard on all the hens. I don't use artificial lights to encourage laying. With our cold temps, I don't want to stress them out. I still get enough eggs in the winter without lights.
Also, I have a number of production hens that only lay good for the first 2 years. Then they really slow down on laying eggs, get sick, and sometimes die. I won't butcher a chicken that has died from some unknown malady. I just toss them into the tall grass out back. Better that I harvest them when still healthy, so the meat does not go to waste.
Like you, I don't treat my chickens as pets. If you want cheaper eggs, feeding old hens will not work for you. If your chickens are pets, then I guess it does not really matter.
I don't think most consumers here in the US know, or even care, about the welfare of the chickens. It's never something I thought about when I went to the store to buy eggs. We have some labeling on our eggs, but there are no real standards and most of it just seems like marketing meant to fool us.
I think the people here on the BYC forums do know how to treat their chickens better, give them a better life, and maybe the "free" eggs we all get are better for it.
I still have a couple of commercial wire chicken cages from back in the 1970's. Each compartment was about 12X18 inches, for 2 chickens. That was their life. I think they were called battery cages. My dad bought some of those cages from a local commercial chicken farmer that went out of business. We used the wire to remake them into much larger hanging rabbit cages.