The complexity of the plumbing, electrical, sewage, yada, yada, yada, would be ridiculous vs. the minimal electrical and fuel/brakes of a truck. Add the structural integrity issues of a vessel in rough seas and wow!
The USCG added to their Island Class cutters (IIRC), and after a few years, started having integrity issues with the added sections. I forget what the corrections costs were, but it wasn't cheap!
I wonder what it cost to add the mid section to that cruise ship compared to building a new one?
Very cool video.