Two newly discovered Apple patents reveal how the company may be working to improve the battery life of its devices. One seeks to eliminate potential wasted space inside an iPhone while the other would utilize smart technologies to control battery swelling.
https://www.notebookcheck.net/Apple-patent-points-to-larger-batteries-in-future-iPhones-by-eliminating-wasted-space-and-using-anti-swelling-tech.527549.0.html
Just remove the cameras. After all, like the headphone jack, it's just "wasting space". Then sell discrete cameras with integrated gimbles to iPhone users, and call it a revolutionary innovation.