I would go so far as to say that the vast majority of the time, systems that evolved are robust, not brittle, and you're right, this compromise "works better" or is "good enough to reproduce more than my relatives". And other times something gets caught in a local minima- but other bits around it optimize anyway (I think the "backwards" human eye might be an example of that- https://en.wikipedia.org/wiki/Evolution_of_the_eye#Placement and see also, https://en.wikipedia.org/wiki/Evolutionary_baggage).
Anyway, the example I was thinking of is here: https://en.wikipedia.org/wiki/Diffusion-limited_enzyme where some enzymes have evolved to reach extremely close to the maximum rate of catalysis limited by diffusion rates (and some enzymes have clever tricks to get around that).