I'm ok with this. My 5s seems to be the exception to the rule as it lasts all day on a single charge with no problem. Even with heavy use the battery percentage does not dip below 40% by the end of the day.
Yeah my aging 4S and my partner's 5 both fit within that category as well. We both unplug them at 7am and have ~75% battery left when we go to sleep. They already last all day and more! When I traveled last week my 4S lasted for 2 days (just) because I was aware of the battery usage and rationed it appropriately.
IMO the iPhone is the best phone out there in terms of battery life because proportionate to the CPU, screen size and overhead of the OS it has the best battery life. A battery that's twice the size doesn't last twice as long if you have a phablet-sized screen, hungry quad-core CPUs and a bunch of JAVA-based apps running in the background (with a less energy efficient version of multitasking).
IMO if your 5S battery isn't lasting all day you should take it into the Apple store and get the battery checked out. My partner's battery was struggling because she used to always use it in bed while it was plugged in and plug it in/use it whenever the battery was below 100%. This killed the battery and in less than a year of usage the diagnostic tool at the store showed she's used waaaay too many cycles. Regardless they replaced the battery for free and she changed her usage patterns. The battery life is fine now!
I think there is some onus for users to understand they are working with highly complex devices with pretty crazily engineered batteries. If you use a $1000 phone like a toy then you're going to break it and get less out of it! Mine's an 'old' 4S but I paid ~$1000 for it back in the day. RESULT? I take bloody good care of it!! No scratches although I don't use a case and the battery is fine... I wonder why when others are battling with newer/more advanced models?