The phones are whatever dimensions they choos to make them. Thicker is an option.
The original iPhone battery life was pretty good.
The current phones life sucks !
Apple needs to put bigger batteries in their phones.
I'm not having a problem with my iPhone 7 Plus and iOS 10.0.2. It's 8 PM and my battery percentage is currently 79% after a full day of work using my phone multiple times during the day. . . and using it during the morning to stream Rush. I took it off charge at 8:30AM.