MEno
Even if rare for an individual collectively it isnt rare.
There was recently a thread regarding parking at hydrants. Most agreed it shouldnt be done. Now what are the chances that when I park at a specific hydrant for 5 minutes, during those five minutes that hydrant will be needed? I say pretty small. However if we all park routinely at all hydrants, obviously that would pose more of a risk. so collectively we all forgo parking though the individual risk is quite small.
while You may have never encountered someone who suddenly collapsed. somebody has. SO collectively if we all learn CPR lives will be saved. It is no longer a rarity it is almost a certainty. This is not the case with a pilot dying. Im not sure if it has ever happened that a pilot (and copilot?) have died on board (aside from being murdered which is a separate issue).
Secondly the practicality needs to be weighed against the rarity. flying a plane is complicated training everybody to fly is expensive. Even if pilots were dropping as often as people in the street (which they are not) it still wouldn’t be practical to teach everybody to fly. LEarning the basics of CPR is easy, it is cheap. Taking an easy cheap step to prevent a problem, even a rare one makes sense.