--scale scales a rasterized frame-buffer-bitmap to the display-resolution, leading to massive quality losses

Problem

xrandr --scale leads to a quality-loss (generally blurry)

(a)xrandr --output eDP-1 --mode 1920x1080 --scale .5 and (b)xrandr --output eDP-1 --mode 960x540 --scale 1 result in the same Screenshot, however (a) should be a 1920x1080 image and (b) should only use a quarter of the screen (to avoid blurriness).

It is correct that (a) and (b) show the same amount of content and the same relative Windowsizes/Font-sizes, however (a) should have more pixels for the same content, however they end up in the same Screenshot.

actual result

xrandr --scale scales a frame-buffer-bitmap to the display-resolution

expected result

xrandr --scale should scale first and then create raster-image identical to the physical display-resolution, as done by gnome-control-center>Settings>Display>Scale or by gnome-tweaks>Fonts>Scaling Factor.

However gnome-control-center and gnome-tweaks are global for all monitors, and can't compensate different dpi on Monitors.