Simple to explain, I work in 16 bit color space to prevent banding as I use many filter layers and color balance/curve adjustment layers.
When I export, all that goes out the window because Krita, as far as I’ve tested, uses closest-matching color downsampling rather than dithering.
This causes problems with color banding that every other application I’ve tried does not seem to have. As such, after I finish artwork in Krita I must then drag it into a separate program in order to properly downsample from 16 bit to 8 bit as Krita does not have that capability.
Below is an example of a gradient downsampled in krita (left) vs. downsampled in a program which implements Floyd–Steinberg dithering (right).
The implementation of this, plus the previous useful feature of downsampling on export, would speed up the exporting process and remove other programs from the pipeline entirely.