Many freighters have space for the 12 passengers they're allowed to carry before they get reclassified to passenger ship with all the post-Titanic SOLAS requirements those incur.
The first 12 however are easy, they self-select to be low-maintenance, they just get their breakfast/lunch/dinner portion from the ship's cook, and have their cabin. A little electricity, reasonable running water, and they're contend.
Essentially a hotel room plus partaking the staff dinner/in-House-catering.
Most people just can't handle the boredom these days, and many don't have that many days to spare, either.
My brother did this (Southampton -> Baltimore). It's a lot slower than the Queen Mary. He told me when he arrived "You don't know what time is until you've already watched all the movies you bought with you, read all the books, done all the work, and you realize you've still got 5 days left".
And he's probably the most able-to-handle-boredom human being that I've ever known.
The passenger capacity is mostly expected to be used by people related to the shipping industry, basically repositioning people the same way airlines do.
Like you'll have two guys being repositioned and another guy will be there with a clipboard and tasked with something.
The first 12 however are easy, they self-select to be low-maintenance, they just get their breakfast/lunch/dinner portion from the ship's cook, and have their cabin. A little electricity, reasonable running water, and they're contend. Essentially a hotel room plus partaking the staff dinner/in-House-catering.
Most people just can't handle the boredom these days, and many don't have that many days to spare, either.