Barred Rocks are heritage breeds, not production breeds. They are a dual purpose bird, so can be used for eggs and meat. Conversely, a leghorn is considered a layer only bc hardly any meat -they are lean egg producing machines.
winter lighting does not kill off chickens. Nor would it severely limit their lifespan. My heritage breeds get light, but since they aren’t heavy layers, they are not laying every single day. In the winter (not counting molt time, when they do not lay) I will get 3-4 eggs/week out of any of them individually, tops. But, out of the flock, I will get several eggs a day.
production breeds are known to have reproductive and health issues. So, it is common for keepers that want lots of eggs reliably to get new chicks every spring (so there are pullets every winter) or completely replace their flock with POL pullets every other spring.