2. The Gameboy screen was LCD not LED, with no backlight, and had a 2.5 inch diagonal compared to this laptop's 14 inch diagonal.
3. Also if you read the article you will see a technical limitation was that the screen had to be run at full brightness
Reducing power draw becomes increasingly harder as you go down the scale. And in use, it's either "sleep/idle" (not doing work) or "draw power" (however modest).
More likely / practical use for those 40y tech advances: similar runtime & power draw, but waaay more compute power (and RAM). Like 32-bit 100 MHz+ vs few-MHz 8-bitter. Oh and more beefy battery ofc.
A $1 microcontroller + a character LCD (or epaper) could get you there. Leaving software + physical construction.
Surely the state of the art is orders of magnitude better than in 1983? Or rather late 1970's because much of the computer was using tech that was already aging.
If it could run for a year off a pair of AA batteries that you can buy in literally any country in the world, who needs more battery power or weight? Or are you saying a cheap modern low-power CPU + ePaper display gets you there?
More compute and RAM comes for free, but it certainly isn't necessary. That exact machine with a USB-C port for network or external storage would still be useful today.
The last time I was looking into this, one of the more difficult parts was the keyboard. Wired keyboards seem to assume abundant power and often consume 0.25 watts at idle. Low energy bluetooth keyboards are designed with power consumption in mind and use significantly less than that. But it would be insane to install a bluetooth keyboard into a slab computer...
I get that this is a hack rather than an actual product but I'd have expected something more in line with 6 days of continuous gameplay with 4 AAA batteries.