In regards to graphics, they can be somewhat unneccessary if people really think about it. Too much graphics can slow down a web site's load time, if the site is rich in text, without some graphics the site becomes a text book of sorts that the average person cannot bear to read. However when utilized properly, they do provide the visual style and project the personality of the person that created the site that cannot be achieved with CSS alone. It all comes down to the web site creator's personal style. In my opinion CSS cannot entirely replace graphics.
Graphics are everywhere.
At least people with current browser have the ability to turn them off if they don't want to see them. Oh I totally agree. CSS can't possibly replace graphics. I had the idea that you were talking about using graphics as titles, which to me seems unneccessary. Expensive to buy, but the rolls royce of editing packages.