With careful design, knowledge of image manipulation, and cascading style sheets, pages can be made to load in seconds rather than minutes. The power of the web is platform independance. Not everyone uses Netscape. The sight-impared hear webpages read aloud by screenreaders in a robotic voice. Couch potatoes use WebTV and corporate execs use tiny palm sized computers connected to the net by cellphones.
Good design takes into account the needs of all possible users.