i don't understand this line of reasoning.
flash allows for compression of video, audio, bitmap and vector graphics, 3d graphics, embedded fonts etc within an extensive api which can be compiled cross-platform and deployed in ria and desktop scenarios.
in the absence of web standards and similar functionality from browsers, it has filled the gap because browser vendors couldn't get their act together.
the plugin comes included in some browsers, and for others it's a small download which ensures a consistency of user experience across the board.
for the developer it offers saving in time and cost because there's very little need for cross-platform hacks.
sorry to be blunt, but if your understanding of flash is banner ads, then you don't understand flash.
i'm not saying that flash is perfect, i'm just saying that flash isn't the worst thing to ever happen to the internet. that would be IE6.