The steam engine was almost immediately useful. It may not be used for cars or trains, but it was the best solution for pumping water from some mines.

In the more recent comparison, I remeber using the web in early 1990's, when it was less then 5 years old. (Fun fact: the images thing were still new, I remember each image had a "download" link in case yser's browser did not support them). It was already used, and had no analogies, and most importantly, the pages I were used were _not_ related to web or even CS, it was some physics thing.

It's time to accept reality: we've spent dozens of years and billions of dollars, and the most useful application is avoidance of financial controls. There is not going to be anything more.