GregThe architectural community is divided upon whether or not using CAD is essential for developing and improving designs, but objectively speaking there are clear advantage to using computers to help with a design.
The best CAD tools made for architects to use are capable of a lot more than a pen and paper (although all of that too), as they can double as simulation tools. A simulator massively increases the usefulness of CAD, as it can remove a lot of the guesswork out of designing buildings. An architect is able to work a lot more quickly, as they can design a building and check the physical efficacy of those designs simultaneously.
In architectural design, making sure that the building that has been designed is actually possible is one of the most important parts of the role. The value of CAD is clearly in this area, as it makes this part of the process a lot more efficient. It could be the case that we end up with computer systems which will be able to suggest possible materials that can be used to accomplish the physical requirements of a structure too, although that has yet to be developed.