The whole thing is absurd at this point. There are so many points of contact that aren't testing at all from air travel, pre hotel stays, shore excursions / diy shore visits, etc.
People live and work in close proximity all of the time - I don't have to get a COVID test to go to work where I interact closely with dozens and dozens of people every day. People who go to stay at an all inclusive resort don't need to test, the list goes on.
At this point I would say that at least 50% of everyone I know has gotten COVID at some point, and that's only the people who had symptoms or close contacts and tested - I bet the number is much higher in reality. We'll all triple vaccinated at this point, can we just give up on this testing charade already?
From the article linked above "Yet, since the phased restart of cruise travel in July 2021, there have been no critical emergency situations where any ship has been overwhelmed with the need to evacuate guests due to a crippling outbreak of COVID-19."