I agree that there are a million other things to worry about when raising chickens, and I'm not criticizing your husbandry practices. Supplemental lighting is perfectly valid and effective. I'm only answering the question asked in the original post.

I understand your other post now. I thought you were implying that your hens did not increase in production despite using artificial lighting. Molting is a much needed break period, but so is the natural changing of seasons.
Of course a hen that has never seen supplemental light will eventually stop laying, but she will last longer than one that has never stopped. That's just logic.. there's only so many ova in the reproductive tract. If they use it up faster, they'll run out faster.
Here's one study's abstract that talks about increased ovarian cancer in hens maintained under supplemental light year round.
https://www.ncbi.nlm.nih.gov/pubmed/4104488
"Adenocarcinoma of the ovary is the most common epithelial neoplasm in the entire body. The relation to egg production was demonstrated in an experiment where adenocarcinomas were induced in the ovaries of 17 out of 19 hens by maintaining them throughout life in a stable environment with 12 hours of fluorescent lighting daily. Egg production rapidly reached a maximum; it then declined over 3 years, with no seasonal rest periods. No tumors appeared in control hens kept under normal lighting conditions with seasonal variations."
Fatty liver hemorrhagic syndrome is primarily caused by incorrect diet, but high levels of estradiol also contribute. When estrogen levels rise in order to start and maintain egg production, the fat stores in the liver also consequently increase, predisposing the bird to FLHS.
Not sure if you can read this full article or not, but there is relevant info in there (not so much in the abstract).
https://journals-sagepub-com.srv-proxy1.library.tamu.edu/doi/full/10.1177/0300985813503569