How is having to "just know" that you have to type www to get that page to load, despite it being presented without www a step forward for usability for technic

How is having to "just know" that you have to type www to get that page to load, despite it being presented without www a step forward for usability for technically unsophisticated people? It just seems confusing to me. I get that it looks "cleaner" but I am having a hard time figuring out how it makes anyone's life easier, or how it actually makes the web more usable.