I too can get by the full day without needing to charge it...i guess its become some sort of standard to rate the battery longevity with on screen time. Also, by people living a lot of them im sure use their phones for business purposes...personally, i dont need to be using my phone throughout the day but many of my peers do, and since they're always moving would prefer to have a big battery rather than looking for charging. But you're right, there are many other available tools at our disposal if required.
When i look into a phone i consider performance, screen quality, size, camera and battery. So based on my assessments, battery is 1/5 of my total importance. Why you ask? Im not so sure anymore, i do have chargers where ever I am and have never been in a situation "OMG my phone is DYING!!", i usually prep in advance (i.e. if im gonna use phone as a GPS, bring my charging cable in the car). Battery measuring is more something we've been fixated to analyse.