For the last 8 years I have been developing my skills as a web designer. The great thing about being a web designer is you NEVER stop learning.
The programers for firefox, IE, safari etc are constantly improving their browsers PLUS things like HTML and CSS keeps getting better and better so it's the job of the designer to stay on top of things to ensure you can offer the best site for your client at a specific time.
A couple of years ago, FLASH was the bees knees.... Then Apple decided they don't want to support that, no we have to find other ways of animating for websites. That is just one example.
Even though I prefer to use CMS like Wordpress or Joomla! I can just as easliy build an HTML site from scratch. I just believe in working smarter, not harder. Start from a decent platform and build the best site on that that I possibly can.