Why do you think the risk of batteries failing in under 2 years is suddenly a non issue? You suggest Apple are being kind by trying to expand the life of iPhone users batteries with an update but why is the lifespan suddenly so short? My daughter is still using my iPhone 4 and it’s been charged a few thousand times in its 7 year life. Sure it’s slow but the battery hasn’t failed.Just the battery lifespan, which is not new or unique to Apple. What was new was Apple attempting to prolong the lifespan of older devices with degraded batteries rather than simply letting the devices fail outright. A battery replacement is perfectly valid and I do not see Samsung offering a similar deal. They drop their old models like hot potatoes.
Personally if my 14 month old iPhone 6S started to experience behaviour where it was suggested I needed a new battery, I’d be pretty pissed off and not willing to pay a fee for a replacement. If it came to that I’d be considering arguing the ‘sale of goods act’ for the product as if it’s failing in under 2 years use, there is reasonable reason it wasn’t fit for purpose as it was sold to me on a 2 year contract.