If you put them in a central "barrel" like in a current plane it would be a bad use of the available space.
Yet you can't do otherwise. Because of the heavy banking when the plane turns, you can't seat people far away from the central axis and closer to the side edges of the V shape.
Makes me wonder if we'll have cargo-only planes that converge on a different optimum. In full autonomous mode, comfort is not a factor and reliability can also be relaxed. Of course, we'd lose the flexibility of being able to convert the plane for passenger service.
This is why old planes long since retired from passenger service are now used for cargo flights, which have an 8x higher accident rate. https://www.npr.org/templates/story/story.php?storyId=212692...
Pilots don’t tend to roll passenger aircraft. But given enough altitude and skill they probably could without spilling a tomato juice on a seat back tray table.