I'm not sure where you are getting this. According to the CPSC, who analyzed some 10s of thousands of fires, something like 50% of them were caused by wire arc

I'm not sure where you are getting this. According to the CPSC, who analyzed some 10s of thousands of fires, something like 50% of them were caused by wire arcing that could be prevented with AFCI breakers. This is the exact reason why the NFPA is moving the NEC towards eventually requiring AFCI on every circuit in the house.