"Computers are to design as microwaves are to cooking." Milton Glaser
Speed is one consideration. That is, the computer and desktop publishing software make certain pre-computer design and prepress tasks faster. But it doesn't really change the fundamental principles of graphic design and good prepress, just the method of preparation. And this quote is becoming a bit dated. There was a time when both computers with desktop publishing software and microwaves were new-fangled tools. These days, it's all that many designers (and cooks) know. Get more insight into this Glaser quote and other quotes on the meaning and purpose of desktop publishing.