OK, so most of the world's population has some form of high speed internet. I'll wager that most of the world, geographically speaking, doesn't. It's not available where I live, probably not for another 2 years or so.
There's only dialup here, which had been adequate when websites were designed with that in mind. Now we have an excess of bloated image-laden sites because everybody assumes everybody else has a fast connection so it doesn't matter. It will always matter. Bandwidth is bandwidth, and if some web designer is stupid enough to use lots of images just because they look pretty, that's a little like driving a V8 just because there's already a lot of carbon in the atmosphere. It's a waste. Now matter how fast the connection is, it will always be slowed down, and to a minor degreee so will everyone else's connection because everyone has a finite amount. Even if you've got a fiber optic conection capable of real time video, it's still limited. And somebody else will always have a slower connection.
What's it like being on dialup? If I go to froogle.com and look for something I want to buy, follow the link to the vendor's site, add it to my cart and checkout, that's usually about an hour. It's not just slow, it's unreliable: I get disconnected about once an hour no matter what I'm in the middle of. I've got a free OpenBSD shell account on devio.us that I can log into, start a program called screen, and then be able to reconnect to my session if I get disconnected.
Some websites I visit seem reasonably fast. Others act like they were programmed by artists or something because they take forever. eBay has always been slow, Google seems to have just gotten slower, but Facebook is completely ridiculous. They have that "suggested friends" feature or whatever they call it where everybody that's a friend of a friend shows up, complete with a picture that may or may not be relevant. I've let it run for over an hour and it never finishes loading. It just sits there and keeps loading more and more images. It's a nice feature, but I don't need pictures of these people, at least not at that point. It takes so long to load all those pictures that loading the list never finishes, which is what I'm interested in.
The "new" Yahoo Mail, unavoidable since about mid 2011, is another one. The old one wasn't too bad, but the new takes like 2 minutes just to find out if there's new mail. Of course it's refreshing all its advertising, which is another complete waste of bandwidth. Then it sits there and wastes more bandwidth for a minute or so after that doing something. It expects to have a full-time connection and whines if it doesn't. My laptop is on 24/7 with Firefox open, and there's only an internet connection about 2 hours a day.
I've been writing HTML for web pages for about 17+ years. It's not very complicated, and the more efficient pages are the simpler ones.