I use all three: chrome for general browsing, Firefox for compatibility browsing and the occasional use of a flash downloader plugin that, as far as I know, Chrome doesn't have an equivalent for, and Internet Explorer for government websites and other sites that tend to pitch a fit anytime you don't use something from the very narrow list of browsers they were designed for (I seriously had to borrow my mom's laptop to fill out the FAFSA last year, because I was up to date on all of my browsers, while the government was up to date on none of them -- not even IE.)
By the way, 2004 was not the first time IE had any competition. When I was growing up Netscape -- the browser from which Firefox is descended -- was most the browser of choice for most people who weren't on AOL. Netscape, in turn, was the direct descendant of Mosaic, the first web browser in history. IE was a relative latecomer.