Web pages use a data source behind the scenes, but web pages are NOT a data source. A rendered Qt app is not a data source either. weboob builds plain-old objects (or JSON), it is a data source. The Qt applications are just an example front-end using weboob data source as a data source. Furthermore, this data source is made for aggregation/standardization, as weboob returns results in the same format whatever the site you choose, so it's still better than if each site proposed an API specific to the site itself.