The Web 2.0 movement was about opening up the data in computer consumable formats and APIs. Nothing more.

While exchanging data over the internet is obviously nothing new, having large organizations provide easy programmable access to their private databases was somewhat revolutionary. The whole App craze was born out of being able to create new interfaces to existing services, thanks to Web 2.0.

Web 2.0 was nothing new from a technical perspective, but it was a revolutionary social shift.