It’s not the ships it’s filthy people they hire
The passengers are the people spreading illness. I remember on a couple of cruises I went on. The first was a woman who was coughing and hacking when she first arrived on the ship ( noticed it on the first cruise day).She was on a tour bus that I was on, and the passengers behind her, and me and my husband across from her all came down with covid. The other passengers reported their illness, and were quarantined. My husband got sick , and he stayed in his room while I got food for him.I didn’t let housekeeping come in our room. I got sick after we returned home. The second time on a cruise (when there was a respiratory virus going around), I saw a passenger sneeze into his hands and then touch the serving cutlery. My husband almost had to restrain me from telling this guy off. I reported it to the manager, and they had to sterilize the whole area. Next time, I will say something to someone who does that., and just not tell my husband.