Actually by a factor of four if we assume that the virus managed to reach everyone it was going to reach on the cruise ship and doesn't spread better on land.
And if only those 712 caught it, that reduces your number by a factor of five. So we are already down from 4.9% to between 0.5% and 0.625-1.25%.
Looking at the data from https://www.worldometers.info/coronavirus/
It seems logical to state, at least within the US, the accuracy of deaths due to COVID-19 are more accurate than total cases of COVID-19. There are a lot of asymptomatic people out there. Even if someone has it with mild symptoms they are told to stay home and only reach the hospital if symptoms are severe. Deaths are more accurate as I assume a test can be performed posthumously for COVID-19.
So, even with this exaggerated ratio, the US has 5 deaths/1M pop. One can reasonably argue this might've been worse if no quarantine measures were in place. However if the true rate is less than 1%, I think the economic effects will be more impactful.
The above link also shows ~27k deaths worldwide due to COVID-19 at the moment. Italy had ~25k deaths due to the flu alone in 2016/2017.