We are starting to see metal filaments and even this copper one[1]. Multi-filament fdm printers just might be able to make some rather large circuits. I doubt we'll get down to 0.2mm tracers, but if size isn't an issue, we can do better than the conductive carbon tpu(?) filaments which are common today.

[1] https://www.gsc-3d.com/3d_materials/copper-filament/