A very good point, Alan.
It is claimed that new technology is capable of identifyiny whether electricity is being used to, say, run a motor, or to make an arc.
It was posited that many electrical fires start when a wire is xomehow damaged - leading either to an ard between two different wires (parallel arc) or between halves of a broken wire (series arc).
Therefore, in 1995 a campaign was started to require the use of this new technology in our homes. We call this "AFCI protection," or 'arc fault circuit interrupter protection.'
Mind you, this is different from the principles used by RCD, GFI, overcurrent, and overload protection. Currently, it is available only as part of a circuit breaker.
The entire subject is still a matter of contention; the devices and code requirements have both had major revisions.
