These graphical tools have a dual purpose: explaining and seducing.
It is very frustrating for both, technical and client, that the second one does not understand what the first one have thought. This is one of the few advantages that I can see today of having studied Architecture: being able to read plans, no matter how complicated they are. However, most people have not received this kind of education and the mental process of spatial information interpretation is difficult and sometimes, impossible to solve.
This is the raison d’être of commercial floor plans.
Using 2D and even 3D mechanics tools, you are able to make technical drawings more intelligible. Architectural technician have to make this effort of spatial understanding too. There are buildings easy to understand when they are built, but it is not that simple on a plan.
Therefore, architecture not only is “written” on floor plans. It also needs sections and elevations, the other spatial projections.
Sometimes, performing axonometric views or sections become in the best visual tools.