Poorly rendered icons when using UI scaling

When desktop UI scaling is enabled, the raster elements of the QtCreator UI are poorly scaled and look overly pixelated. In case of the sidebar on the left in the Classic theme, the icons also look too large so that some of them get clipped.

The attached screenshots were taken in KDE, when the scale factor in the system settings was set to 1.7. Fonts DPI was not set and Qt auto-scaling was not enabled.

I would prefer if scaling of the raster elements resulted in a smoother image without the excessive pixelation. The size of the icons on the sidebar probably needs to be reduced.