Yes but all else equal, lower resolution screens will have better battery life. They require dimmer backlights to achieve the same brightness level, and the graphics hardware doesn't have to work as hard (or be as powerful). For phones, resolution starts running into diminishing returns around 300ppi. The Nexus 6's 493ppi sacrifices significant battery life for practically unnoticeable resolution improvements.

Phones with larger screen's generally have better battery life than phones with smaller screens. Look at the iphone 6 vs 6+ for instance. Increasing the screen size leads to disproportionately more room for battery since most of the other components dont get bigger as the screen size does.

I agree that we are at a time when battery life should be prioritized, but I would prefer that to come from thickness. Increasing the thickness by just 25% or so would allow a much larger battery.

We're not necessarily arguing against screen size, but pixel density. That is, instead of scaling the resolution linearly with the screen size, they did that and some. So now instead of a low 400s pixel density range like the Nexus 5, the Nexus 6 sits at a de facto PPI of roughly 500.

Obviously there's a cost to this, both in battery and hardware requirements to push those extra pixels. Meanwhile nobody can detect pixels on a Nexus 5, but apparently it wasn't good enough.

And next year we'll see PPI at 500-600. I just don't get it.

As for thickness, I think the Nexus does quite well. It's about 50% thicker than the iPhone 6 which is a great number (~10mm) to be at in my opinion.

additionally, no one can seem to detect the difference in battery life between 1080p and 1440p. Without having stronger data I have to lean towards the backlight taking up enough power that the difference in cpu/gpu work makes little to no difference.

Whatever the hell the technical issue is -- more battery life is far more preferable to better displays.

Dumbphones had great battery life.

Yet we use smartphones...

Anyhow, my Nexus 5 lasts the day, I plug it in at night. That's good enough. And I like the screen.

Battery life only matters to a point - after that features and niceties matter more...

Agreed, but what "feature" does a 1080p display provide over a 720p one? The smartphone/dumbphone comparison doesn't really work - there are no new features here.

For one, reading text is much more pleasant.

For me, slightly more pleasant text reading is not worth battery life. Reading text on 720p is absolutely fine.

First of all, the battery life improvement with 720p vs 1080p is negligeable. Screen size and brightness matters more.

Second, there is such thing as a 'good enough' battery. For most people, this has been achieved with the current crop of big screen, high res phones.

Not sure why you think people would accept lower resolution for an extra half hour of battery life...

What's the point in having more hours of battery life than your own number of waking hours? No one has ever adequately explained this to me.

Say I forget to charge my phone during 20% of the nights. A battery that lasts a single day will fail me very often compared to a two-day battery. Not to mention that unlike "dumb" phones, the iPhone won't turn itself on automatically to wake me up in the morning. Also, battery life is measured for "normal use". If you are draining your phone eg. by using it for directions in a friend's car without a charger, then it's suddenly more like 4 hours of battery life.