I Phone battery Sucks and when this will be improved?

IMO:  This question would be better put to Apple, I think, as it involves details of Apple technology that Experts Exchange has no control over.  (But the fact is, no matter how long a battery lasts, it's never long enough.)

Turn off email fetch. Off completely and check manually, or check once per hour.  That is the biggest drain.

Next, make sure the screen turns off in 10 seconds or less. That is the next big drain.

My iPhone battery goes all day.

Be careful what applications you allow background use.
Also review Settings > Battery for any application that drain the battery.

Added Apple topics.

As Dr. Klahn has described, people here at Experts Exchange will not have an explanation for how Apple's engineers are 'not looking at battery side.'  We can only hope they will always try and improve battery life on iPhones.

John's and Shaun's comments are typically the first things to check when there are battery drain issues on the iPhone.

Of course it's all very subjective as to what one person vs. another thinks is satisfactory battery life for a smartphone. I can go for sometimes two days without recharging. I think that's great! I manage several iPhones and when a user complains of short battery life and the above suggestions do not resolve the problem, wiping the phone and reloading iOS always worked for me as a last resort in the few times I've tried it. It's hardly ever a worn out battery. If you have your iCloud backups in order, are on a cloud service for email/contacts/calendar, it's quick and painless process to rebuild an iPhone. It's also a good idea to delete any apps you no longer need first. Poorly written (free) apps are sometimes the culprits in premature battery drain.

I do use Iphone in every half hour,
When its time to click selfie
MMORPG games
5 Emails id configured on my Iphone and syncing regularly but compare to samsung smarphone Iphone's battery performance is not good.
I dont go to to bad apps but with only recommended and reliable

really admit it as the drainer reason #1
but on my other smartphone no such issues
I guess I should remove games once and check whether it works or not
:)

yes the gaming issue is drainer reason #1