Removing staircase artifacts in image/mesh

I have a micro-CT scan of an object of which I would like to visualize its mean curvature. When zoomed in on the generated isosurface’s mesh a “the stair steps artifact” becomes visible:

Mean curvature:

I would like to smooth out these serrations/lines to make the distribution of colors more smooth. The original imagedata has already been smoothed using Gaussian blur. However, I cannot increase the strength of it much more without loss of other information in the image.

I also tried multiple combinations of filters such as decimate, subdivision, smooth and generate surface normals. Applying this will remove the stairs but always seem to introduce new artifacts:

I was wondering if anyone would know a correct way to get rid of the stairs and if it would even be possible to achieve this using Paraview (or VTK)/. Any suggestions are appreciated!