Neither was user generated content (that's what the original web was) or social networking (irc, email, bulletin boards, etc). Making it useful and usable beyond an academic and techie niche was new.

> Neither was user generated content (that's what the original web was)

The fall and return of the cat picture still amuses me. In the early days of Web adoption when people would put up a personal home page just for the thrill of having one, stereotypically the only bits of content they would be able to come up with for it were a list of favourite bands and one or more scanned-in pictures of their cat. So for years and years afterwards cat pictures were a synechdote, a punchline for jokes about the naïvety of the early Web. Then phone cameras and low-effort social media became big, and ...

And more, the AI hype-cycle was definitely on the upswing again already by the beginning of 2010. The Netflix Prize and the motor-vehicle DARPA Grand Challenges were all 2000s events, for instance.