STD breakers don't see propagating wave forms from all directions.
A solitary Leviton AFCI outlet, per 406.4D4, typically trips when Plug-on breakers start burning up a bus stab, so critical maintenace can avoid further destruction.
Panel flippers want to replace the box, wont pay for skilled talent, and have financial incentive to let it burn down.
In my opinion series arcing is the end stage of joule heating, provided combustion has not already initiated. Better splices, connections (screw vs back stab) and bus grabs would be a better solution than mandating costly devices which do not address the fundamental core issue at hand.
I think if someone was going to incorrectly install equipment out of indifference or lack of knowledge, they probably won't install AFCIs either.