One of the beauties of complex systems is that these individual failures do not produce system-level failure unless you are extremely unlucky and they all fail

One of the beauties of complex systems is that these individual failures do not produce system-level failure unless you are extremely unlucky and they all fail simultaneously. If you are simply counting the number of failures, complex systems do look a lot less appealing than simple ones. But if you count only catastrophic failures, complex systems begin to look more worth the energy tax spent maintaining them. This is the guiding design principal behind most biological, social, economic, and (now) internet-related systems. I don't even think it is intentional. It is simply the best solution so it was discovered by natures and is constantly rediscovered by engineers.