There's a big difference between saving a few hours and saving a few days. The ship will likely also be quite a bit more money and have a very limited set of departures. And somehow I doubt very many companies are going to give you that time off and pay for your trans-Atlantic trip on the Queen Mary 2. I doubt most companies would be big on you taking a trans-continental train trip in the US for business either. (Though I've taken overnight trains in Europe.)
The queen mary 2 is expensive today because it is nothing but a luxury tourist trip. Back in 1950 when there was serious ocean liner travel, an ocean liner ticket was much less than a transatlantic flight. Trains were also substantially cheaper. It is only absurd today to travel long range by ship or by train because people overwhelmingly paid a premium for faster travel to the point that the market for the other methods collapsed.
I suspect that it's mostly that air travel has gotten a lot cheaper relative to other modes of travel. It's true that you can't really travel "in the back of the bus" in an ocean liner any longer but I doubt if roughly equivalent first class tickets and dining are all that more expensive today. (Although I haven't done the calculations.)
Even today, when there is essentially no utilitarian travel by ocean liner, a transatlantic crossing in a balcony room on the QM2 is $800. An economy flight from new york to paris on Air France is $849. First class is $9,262.
That sounds more like what I'd pay for a round-trip economy ticket to Europe and there are probably going to be other costs for lodging etc. associated with the ship. But, fair enough, like (sometimes) long distance train, air isn't necessarily hugely cheaper.
(And, yes, business or first class that you actually pay directly out of pocket for is priced like a luxury good. Of course, you can pay a lot more for the cabin too.)
You can get a taste of this when you look at the cost of long distance rail— for example, a trip like The Canadian (four days in total), which VIA understandably sells as a cruise ship type experience rather than practical travel:
Obviously some of the cost difference is just the massive economy of scale enjoyed by airlines, but at the end of the day there are certain fixed costs associated with being in their care for such a long period of time. Even with a cheap ticket where you don't get a sleeper bed and have to buy/pack your own food, they still have to staff the train that whole time.
The last time I needed to go to Chicago (from Boston), just for kicks I looked at taking a sleeper train. There was really no way I could justify either the time or the money for a business trip.
I did take the overnight from London to Edinburgh a year or two ago. It was actually pretty convenient but it still almost certainly cost more than flying.
> somehow I doubt very many companies are going to give you that time off and pay for your trans-Atlantic trip on the Queen Mary 2.
Honestly, I'd guess that depends on your job function, whether you can work effectively remotely, and the cost of the ticket.
As a remote employee, I can totally see justifying it to my employer. It wouldn't be typical, but if it costs about the same and the trip there and back would involve me getting as much or more done than I normally would... I'd definitely pitch the idea, and don't see any reason why it would be out of the question.
In fact, I'm making a mental note to investigate the cost when/if I need to attend a conference or something in Europe.
Of course, who knows if the option will even exist any longer. Costs cover quite a range but they're probably more than a business class ticket and there are relatively few straight ocean crossings (vs. longer cruises).
