Let’s not get too crazy. There’s a 15 year period where young men tend to get injured and young women tend to give birth that acts as a major filter. If you plotted death rates on a graph it would look like a trident – that’s life without antibiotics.
It’s certainly true that elderly were not a rare sight, but those elderly who could be found were almost universally hardy of constitution or talented at avoiding danger. Quite literally the end of the bell curve.