The banding is a multifactor isue, for example that image in my computer:
minimun to no banding:
- Inkscape
- Gimp, svg or png export from Inkscape
clearly visible banding:
- built in windows viewer suing a png export from both Gimp and Inkscape
The reality is that the cause of the banding can be related to various reasons:
- bad image conversion
- color space management support in both app and/or in hardware
- display calibration
- display hardware
- color depth
- the image
In the case with the image that you uploaded the banding have 3 reasons one is "color space management" and the others are "the image" & "color depth" as it only uses 48 unique color in 8bpc, in that case the only solution is to use dithering to hide the banding.
This is somewhat related:
https://askubuntu.com/questions/8069...-for-gradients
PD. One posible solution is to render the svg in 16bpc and the convert it to 8bpc+dither, regrettably I don't know how to render the svg in 16bpc, but the color conversion with dither can be done in imagemagick.