The main problem is that all large cruise ships are very tall, narrow, and have long, flat sides, and are basically designed to roll on the water in heavy seas.
What keeps the cruise ship from rocking is continuous active stability control powered by hydraulic and electric drive from diesel generators. This drives the massive "tuna fins" that deploy on the sides of the ship at sea.
When the diesel fuel runs out, the fins can no longer be adjusted, and the ship loses its stability to prevent capsizing.
Fortunately, cruise ships spend most of their time on calm seas, but in glassy waters they tend to lose power, and large side-to-side movements can interfere with the top deck.
When will a drifting ship run out of fuel? Almost immediately. It won't have any extra reserves, just enough for a 12-day journey or 30 days of drifting.
Modifying a ship to increase its fuel supply while adrift requires laborious work by the crew, which would be impossible if the ship is scheduled to be abandoned. Therefore, it is expected that the fuel needed to prevent capsizing will run out within one or two days of the scheduled arrival date.
Once the power goes out, these ships become toys for the first big storm they encounter.
The first thing that happens is that the cabin is repeatedly and violently tossed around by the wind, with enough force to break down doors and tear off bolted-on beds and chairs.
If they rotate violently several times, loose furniture and debris can shift, causing the trim to come loose and increasing the risk of accidents. However, because their superstructure is divided into very small sections, most of the debris tends to stay within 20 feet (about 6 meters) of where it once stood.
That is, until the welded joint starts to break.
Welded joints are a weak point in modern ships.
This is a cruise ship being scrapped at a dismantling yard in Türkiye.
Take a look at how it's being dismantled. It's being taken apart just like Lego blocks, isn't it? That's because it's made of blocks.
Next, I'm assembling Royal Caribbean's Oasis of the Seas. This is also made of blocks.
A typical modern shipbuilding house-sized block awaits its turn under the cranes:
When modern ships are pushed to their limits, failure occurs along the welds between blocks.
This is the state the Norwegian Dream, which collided with a container ship in the English Channel, is in. You can see that the block under the bow is easily torn apart. Also note the 10 tons of rented cargo on the deck!
A drifting passenger ship begins to rapidly disintegrate once the welds between its sections start to fail.