I’d love to be literal devil’s advocate here and argue devils just think different, in ways usually not immediately beneficial to in-universe society but ultimately a plus by instead providing a stress test for development of what is in universe considered ‘good’. Insert the quote from Legend what is light without dark.
Always interpreted planar creatures as having an alien thought process in general. That is a good use of devils ngl, for related playing pallies/clerics with ‘my higher power is the people’ is quite fun.