I'm smashing up some concrete steps so I can repair them by pouring fresh concrete, and noting that the previous fellow (or hardy concrete pouring gal c1911-1950) did not have the benefit of Quickrete premixed bags to which I just add water, mix in wheelbarrow, and pour.  

They probably had limited concrete expertise as I'm finding big chunks of rock, no rebar material (metal to help strengthen the hardened concrete), and even a glass bottle buried in the steps.  Even I wouldn't toss in a bottle…but….

But the point is that that hardy concoction worked well for many, many decades.   It was a mediocre job but it was the RIGHT job.   Probably close to the same project lifespan as if they'd had the world's BEST concrete people working on the project – and even if the BEST concrete people's job would have lasted forever, it's likely somebody might have come in to remodel or otherwise destroy the "perfect" job.

The moral of the story is that in most cases the "perfect" job is NOT THE BEST THING TO DO!  In almost all endeavors it's better to have much higher levels of mediocre production than a modest level of high class production. 

"But would you want a doctor who is removing your spleen to believe in your principle of mediocrity?"  You ask, expecting me to say …. "that is an exception".

 It's not an exception and neither is national defense spending, which is absurdly expensive partly for political reasons but mostly because mediocrity is not valued highly enough in this venue either. 

I say we need MORE mediocrity in almost ALL things, especially those where risk aversion is most expensive such as national defense and offense, health care, and social security – our triple threat national budget breakers.  

Most of the world lives (and dies) with very modest levels of health care.  Here in the luxury world we can live a few years longer thanks to super advanced medical procedures, though most of  us squander those benefits with lifestyle decisions like smoking, overeating, and poor excersize habits.

The case for the massive interventions and high level expensive healthcare options we insist on in the first world is not only questionable from a practical standpoint due to very low ROI for high level interventions – it's questionable from a moral one – at least until the majority of people in the world have *basic* health care.