Systems that are robust due to being simple, flexible, highly independent tend to peter out over the long haul, as their failure is often an effect of a changing environment rather than some internal fracture.

Anything that's made "robust" artificially (like propping up a bridge with a loose piece of lumber, or injecting bailout money to maintain bank's solvency) is now completely dependant on that artificial prop. if the bridge is allowed to carry more traffic after being propped up this way, you can expect a catastrophe equal to the one you averted + everything that's been added since.