ESD kills chips rather directly. There is a closed loop from electrostatically charged person to ground, flowing through a semiconductor junction. Thousands of volts is not out of the question.
With EMP - if a device is stand-alone (not plugged in or connected to something else) there is nothing to efficiently absorb the radiated energy of the EMP pulse, what energy is absorbed is generally far less than that required to bridge and destroy a semiconductor junction
So watch, cellphone, etc. are not likely to absorb enough energy to destroy it - if it’s in your pocket, or on your wrist.
That’s why ESD is different from EMP.
but you still have ESD issues with boards, not just chips, I still have to wear my wrist band and stand on the mat...
With a million volts flowing through the air, i find it hard to believe that much of an over voltage of electrons is NOT going to cause heat inside chips and fry them, each circuit is closed to some extent from their power source to their ground, it may be small and short distance, but it is still a path for flow...