Why did the Apple company fail to produce more battery stability for iPhones ?

[iMore Question]

iPhone's battery is drained by a day if it is used fully.Can't it be improved by Apple

 

[Bigeric23]

I use my iPhone 6 Plus for 2-3 days before it needs a charge, so . . . I have no issues with battery life. What iPhone model do you own?

 

[Just_Me_D]

The batteries I've had with ALL of my iPhones have been stable and long lasting for my usage. I'm also the type of person that goes through each and every device and app setting and make changes according to my wants and needs. Having said that, is it possible that your smartphone usage require more than the typical battery life of the iPhone? If so, have you considered using a smartphone with a battery life that's more in-line with your usage?