Well you're engine can fail at 4 times the pressure required to turn off the little red light, when at high rpm high loads. This is why racers like
oil pressure gauges, so they can see what the pressure is at those conditions.
The light winking at you at idle is not close to a failure at idle, but what is the pressure when you go WOT. You have no idea. You just know that the light went out.
On a new engine with a clean screen on the
oil pump, the manufacturer can count on the fact that a gear type
oil pump is relatively a positive displacement pump, thus flow is proportional to rpm. However after many miles, the warranty is gone. A plugged oil pump screen restricting oil flow will limit the flow to a maximum. Now the flow is not proportional to the rpm. The idiot light will not show that, only a pressure gauge will show you that. Many an engine has failed to too little oil flow and the little light never came on.
The manufacturer is not overly concerned about this unfortunate event, because one they do not have to pay and two you need a new car.