Per Ms. Kommando:
The average car on U.S. roads is 12.6 years old.
What was the age of the average car on the road in 1995?
Does the average driver drive more miles or fewer miles per year, in 2025 compared to 1995?
I do know that Aluminum block engines are prone to warpage over time, and with warpage, head gasket leakage usually becomes a problem. However, Aluminum block engines were common well before 1995.
It seems to me the sheer complexity of modern vehicles is the primary reason they fail...
Certainly a part of it, tough to test 1,000 systems vs. 100.