Never could get convincing fog out of flat planes in Blender - they always clip through everything and look fake.
Blender 5.1's Raycast node fixed that, so I built BlendFog: fog cards that fade into your geometry. EEVEE + Cycles
Free + full pack: jesperbylov.gumroad.com/l/ayhrrl
Youtube:
https://youtu.be/Kp99uyrD36E