I'm sure manufacturers keep an eye on some minimum standards for battery life over product life - they do have a financial incentive to do so, both from a brand

I'm sure manufacturers keep an eye on some minimum standards for battery life over product life - they do have a financial incentive to do so, both from a brand quality perspective and in terms of the cost of each visit to the Genius Bar / warranty claim. I replaced the battery on my MacBook twice under warranty, I can't imagine that laptop ended up being profitable for Apple.