In BIM 360, 5 years ago, rooms were visible in 3D. After it was deactivated. (In power BI, with the SVF viewer, it's possible to see in 3D the rooms).
Autodesk now has a stragegy for the data inside ACC.
Rooms elements have a lot of useful data for client, designers, construction teams... (area, perimeter, finishes, department...), these data are useful to track the program, the finishes quantities... and to track the work progress on site. It would be great and really useful to have an option to enable the display of rooms in the viewer (3D & 2D).