I wonder though, how much of it has to do with lubricant improvements. I think engines last longer in recent decades has less to do with metallurgy and engineering and more with oil.
Cylinder ridges at the top of strokes was a big thing decades ago. Now, you hardly see it in cars with 200k. Is that cause they’re using different iron and aluminum blocks?
I think it’s because of the superior oils of today vs yesterday. These oils protect better against corrosion, flow better, and last longer.