Better compression, webpage graphics, etc, are often at the back of a web-dev's mind, more concerned with getting the job done and not slamming the server. Now it feels like how many services, flash apps and applets a site can cram on the front page... Even on a fast connection, some sites are slow loading, never mind what is expected of dial-up.
But as Mario points out, it's not just web pages, but internet based services, like games. I can see why companies want online authentication for services, but they come from locations with always-on connections, they have no concept of an unreliable connection. They may think they do with their 1-2 hour outage once a week; but when things get rough, there might as well be no internet.
I used dial-up for many years, from 1996 - 2004. I can say that I would never like to go back to that again, might as well just forget the internet. When it takes 30 mins to download a couple dozen emails, things look pretty bleak. What's worse is non-resumable downloads. A 'small' 20MB download suddenly takes the best part of a day to download. How is one supposed to update a graphics driver when they're 100MB each, let alone a game update.
Here's me moaning about a 60GB/m bandwidth cap... which I still think is an arbitrary limit for no reason - but that's another matter entirely.
Thanks Mario, for a little perspective on the matter.