No you don’t need better than 1080p but most developers need crisp text and I would like to go further and 4k 15inch displays would be perfect for me as it would allow me to have smaller text without a loss of quality.
Obviously, nothing. High resolution for most people is still just a 'nice to have.' But even 1080p@15" will produce relatively crisp text. I'd argue East Asian languages are the only ones to significantly improve in legibility, as sub-pixel rendering pretty much does what it needs to do for English nowadays.
That being said, I absolutely will always go for high DPI and everything, I just don't think it's sane to argue it's an absolute must for what amounts to typing and reading text.
<FourYorkshiremen> Eeee, you were lucky. My first personal computer maxed out at 320x256, or 160x256 if you wanted more than 4 colours. </FourYorkshiremen>
LUXURY. We had 32x24 b&w characters and we were glad of them.
(ZX81, nominally 256x192 pixels but only accessible as 8x8 character cells.)
edit: seems like HN doesn't support these characters but see https://en.wikipedia.org/wiki/Block_Elements
I made a 'zooming through a tunnel' program in assembler once, using them
Although in the context of developing on small screens, they're not very helpful.
(And if you redefined the character set on the fly, you could make things like Forty-Niner. https://www.youtube.com/watch?v=OTTWMIQVznM )
In the manual, there were some programs you could type in, including "Mars Lander". The calculator shows a landing speed (e.g. "8.2") and then you need to type the thrust adjustment (e.g. -1.0 or +3.0) and then the new landing speed is shown. If you do it right, you land safely and it shows "00000" or something. But nah, that did not happen, you just crash ("11111")
Following that, when I got ZX-81 with 32X24 screen, and like, 1Kb of memory, I was in heaven :)
But it's not a requirement for 'most developers' - in fact the ones I know with high resolution laptops don't want them, they're just annoyed by lingering issues with UI scaling and tiny text. I can't think of a sane reason for having font sizes so small that you need 4k to display text properly. Text is plenty crisp at 1080.
Also this is a laptop. More pixels means shorter battery life.
Maybe what you really need is a desktop.
It looks so much better at 2000. Of course you can get by with 1080 - hell, there've been times when I got by with 600 - but when you can see more code and read it more easily, it's easier to get on with development.