Cruise ships make up such a tiny percentage of overall emissions. They're horrible on a individual level, but there just aren't that many of them compared to other sources.
Meat production on the other hand makes up something like 17-18% of ALL global GHG emissions.
Throwing freighters in there like that is a bit sneaky lol The amount of freighter traffic must dwarf that of cruise ships.
Anyway, people on cruise ships are mostly not particularly rich. They're pretty much just water-borne holiday camps.
Each of us has an individual responsibility to making the world a better place and apathetic inaction like this is what allows the rich to flourish. You have more power than you think.