Your counter is 100% correct and exactly how I see it as well.
There has to be a point where the message is just not registering with anybody new and the declining returns amount to nothing.
You would be very hard pressed to find somebody alive today that has a phone who has never heard of Jesus.
+1
You are so wrong! I have traveled through many parts of the 3rd world, there is such a profound lack of biblical knowledge or missionary work in many of the remote areas of the world.