Take a look at Drudge Report
http://www.drudgereport.com/ ... among the most popular websites in the world and yet the entire thing is very simple HTML. A less extreme example, though still relatively simple, is Wikipedia.
Point is, ultimately, content is what brings people in, and keep them coming back.
Also, many people these days are using mobile phones and other hand-held devices that have small screens and limited computing power.
On a related note, HTML 5 unlike previous HTML versions is a constantly changing standard (an oxymoron), and hence designing to that is going to lead to much stress and disappointment. And don't count on downward compatibility either.
Yeah, as you can tell, I'm not a big fan of web 2.0 or 3.0 or whatever the buzzword is these days - I go to a site for a particular purpose / get content and can do without the glitz, which usually does little other than gets in the way and slows load time.