Apple Admits Secretly Slowing Down Older iPhones

Apple settled long-standing conspiracy theories surrounding claims that the company was purposefully slowing down older iPhones in order to force people into buying newer models - and there's a "perfectly good" explanation.
Batteries
In early December, Reddit user TeckFire posted a report in the iPhone subreddit, noting that after experiencing a painful slowdown on his iPhone 6S, a brand new battery resulted in significant improvement in benchmark scores - as can be seen in photos posted to the thread: