Manually maintained directory(SkoHub, publiccodeyml and Wikidata) are able to deduce attributes that can’t be auto-generated from repository data provided by forges. It might be worth adopting indexing-friendly features in forges to better describe the projects they host but IMO, it should be a post-federation goal.
With Starchart, I’m trying for maximum interoperability(with existing standards like publiccodeyml and wikidata) with the data available right now. 