This phone absolutely needs to last all day without recharging. Lower resolution displays draw less power and require less power to render to. 1280x720 is reasonable for 4.7": it's 316 ppi. Higher density only offers steeply diminishing returns in image quality, for sharply increased power consumption and a noticeable increase in cost.

Battery life. When you’re already above 300ppi (312ppi for this phone) it becomes progressively less noticeable to go up in resolution for a measurable hit to the battery life.

Apart from the obvious problems (more pixels = more GPU/CPU power needed), the more dense the screen, the less effective is the backlight: With a denser matrix, less light passes through the tinier cells, and you have to crank up raw backlight strength to compensate. And that is absolutely murderous for an outdoor phone that has to have a backlight as bright as possible, so you can read it in the sun.

Here in the Netherlands the CAT branded phones are very popular among construction workers, even though they have low resolution screens, Android versions that are a couple of generations behind and (surprisingly) batteries that can't be replaced. Raw specs are not that important in this market.

I've worked in construction and I use a Nokia dumbphone. The reason for it is that I need to answer calls quickly while at work. So the phone has to be in a pocket close by. And it's likely that most pockets "close by" also have some sand in them.

Nobody has money to buy new iPhone every two months. But it's manageable to buy new dumbphone once a year.

Similarly I've been scrambling to keep finding new feature phones with rubber-sealed keypads for my dad (car mechanic).

Every seam is an invitation for steel dust, and touch screens are useless when you're wearing thick work gloves.

How about the Cat B100? http://www.catphones.com/en-gb/phones/b100

I've been considering getting myself one, not because of a dirty work but I'd like to have a phone that's usable with gloves on. And a battery life that is measured in weeks, not hours.

$100? Oof. It used to be that you could get $20 Nokias like that.

Yeah, it's a bit pricey but certainly a more rugged phone than a $20 dumbphone. I guess the question is: "will it last five times longer or be significantly better?" I haven't tried it.

They have a few models that are quite a lot cheaper than this, but with less battery life and other specs.

The non-replaceable battery is disappointing, but understandable: a removable battery cover is a seam that has to be water/dirt-proofed, and a point of failure when dropped.