Who are we to say the mechanisms of biology are “overfit”? Maybe it would be nice if our personal machinery was more robust, but that robustness comes at an evolutionary cost. The greater force that is life on earth as a system for regulating planetary energy dissipation does not care about the needs of the individual. It does not care about the fashions of the millennia. Its sights are set much farther and its history much deeper than that

The need to reproduce and repair our bodies is a big trade-off.

Electric motors are sort of like hermit crab shells - Hard and long-lasting, but they only exist because they piggyback off of a living species.

For more complicated organisms, robustness comes in the form of cellular turnover, and regenerative healing in response to injury, at least in youth. I wonder though if single celled organisms have or even need such a function.

That is a fair point to be honest! I guess when you a 20min lifetime you can probably compromise on reliability in favour of extra efficiency

Or perhaps we are "overfitting" for robustness over time and also as a group (over society) vs just individual robustness at any given moment.

We also have extremely robust livers that allow us to eat a super wide variety of food as energy inputs