I can see it for programmers. Here you can use industry standard python libraries (shapely, geopandas etc.). Nobody really wants to learn PyQGIS (the python interface for qgis). So while qgis is much more full featured for "desktop" gis (designed to compete with esri arcgis) i can see the use case here for people who want to build their own extensions and port code from this to other python projects more easily.