This is NOT a valid sample to extrapolate to the population at large. Cruise ship demographics are different: much older, much more health compromised (obesity/O2), and much more mobility compromised than the general population.
These are my observations from a lot of cruises over a couple of decades.
If you use Diamond Princess as a template, the observations skew to a much more deadly rate than will be seen in the US at large. If anything, I’m pleasantly surprised to see the Diamond Princess death rate is, thankfully, as low as it is.
God bless them.
Of course, you do realize that almost a third of the folks on the ship were crew, which are actually younger than normal (and presumably more healthy than normal).
If you want to dig into the weeds here is all the data:
https://www.cdc.gov/mmwr/volumes/69/wr/pdfs/mm6912e3-H.pdf
What is the typical medical staff on a cruise?