Totally agree with you, Thai.
It's absurd to go through the tedious steps of resetting when in the end the battery drain issue persists.
Not until Apple comes with a solid solution, this annoying and serious problem will be fixed.
When my very first iPhone 4S was operating on 6.0.* never had any problems with a short battery life.
Battery was losing only 0.5 % per hour on a standby, getting 2 days of a very decent battery life with browsing, messaging, apps running in a back.
Now, a few updates later, my iPhone loses anywhere between 1 to 4 % per hour on a standby of its battery life, and while doing very light browsing anywhere up to 10%.
Have to charge phone 2 times a day.
The thing is some applications and programs can't function without the latest iOS version, and that's the reason why so many users have to do the latest iOS updates thus finding their iPhones vulnerable to a very short life, screen freezing, Wi-Fi being busted, and being exposed to security scams.
Hope Apple gets, once and for all, those crucial vulnerabilities fixed.