There’s little point in arguing with someone who is determined to simply be a jerk. In fact, there’s little point in arguing at all. I suspect the other readers of this thread already understand the distinction you’re laboring balefully to avoid.
Be that as it may, the average person lived the average life span.
Hello? That is why it was the average.
You know, some lived longer, some lived shorter, but, the average parson, lived on average, the average life span.
Regardless of your personal statistical math.