I think diet, production rate, and genetics in general are all factors. Most issues that I have had with my chickens (all Barred Rocks) were laying related, and they were very high producing in their first year or so (now slowing down due to molting, time of year, and age since they are two now).
I've dealt with one soft-shelled egg layer who recovered (after a vet visit, because she has always had a difficult time compared to my others and she seemed lethargic so I decided antibiotics were warranted), one soft-shelled egg layer who did not recover (she laid soft eggs for months, which calcium didn't help; it turned out she had cancer of some kind), one who was likely egg bound but is completely fine now (there was an egg in the middle of the yard and she was concerningly lethargic for a day, but has been fine since), one who laid soft eggs for months before passing (though I am not sure if it was a laying issue or predator attack), and two separate hens with prolapse issues (one was the hen with cancer mentioned above, and the other had a mild prolapse and then ended up passing months later, but I'm not sure if her issue was laying related or a potential heart issue). I had one other hen pass when she was under a year old, and I suspect an internal laying issue of some sort, because she never looked or acted quite well once they started laying.