They also gave it 2GB of RAM and a better camera. Honestly the variances in what you're talking about are pretty insignificant. The biggest difference is in weight in a whopping 14 grams. Is that really the complaint? The battery is the same capacity, but yes, it's being used differently than before so it probably affects your personal battery life. I don't really have any battery issues.
If using 3D Touch and it affecting battery life concern you, you can turn it off since it isn't a feature you're interested in anyway.
View attachment 589027