[michaelmrose]

The overwhelming majority of the low-DPI external displays at this point are 24-27 1080p

Most high-DPI displays are simply the same thing with exactly twice the density.

We settled on putting exactly twice as many pixels in the same panels because it facilitates integer scaling

[jsheard]

That doesn't gel with my experience, 1080p was the de-facto resolution for 24" monitors but 27" monitors were nearly always 1440p, and switching from 27" 1440p to 27" 4K requires a fractional 150% scale to maintain the same effective area.

To maintain a clean 200% scale you need a 27" 5K panel instead, which do exist but are vastly more expensive than 4K ones and perform worse in aspects other than pixel density, so they're not very popular.