To be fair, once a century refers to average, it is by no means a guarantee that it will be a century before the next crisis.
or more likely, it happens, but because of prior experience, the event is no longer as calamitous as the first time.
Looking at the GFC in 2008, the monetary policy back then was too tight (hindsight 20/20 and all that of course), causing the recession to be extended longer than it would've.
This covid disaster would've caused a similar problem, imho, if the Feds did not loosen up like never before. It "solved" that same problem the GFC produced. Had the GFC not occured, the pandemic would cause a double wammy - a medical problem, and also a monetary problem.
1. https://en.wikipedia.org/wiki/Investigations_into_the_origin...