Feature summary (what you would like to be able to do and where):
Show "Wikidata Query Service graphs" (hereafter WDQS graphs) in WMF wikis, like Wikipedia.

Use case(s) (list the steps that you performed to discover that problem, and describe the actual underlying problem which you want to solve. Do not describe only a solution):
Currently, both Extension:Graph and Wikidata Query Service graphs are trying to show graphs by using data from Wikidata Query Service. Extension:Graph plans are at Extension:Graph/Plans. This seems like duplication of efforts. Instead of trying to emulate what WDQS graphs do in Extension:Graph, why not just show the WDQS graphs on WMF wikis?
Extension:Graph is facing some issues with utilizing WDQS as it has to be in an iframe, as per T334940, using WDQS graphs in WMF-wikis would solve that. The newest codebase of Extension:Graph, as of writing this task, does not support WDQS properly.

Benefits (why should this be implemented?):
At a glance it seems like WDQS graphs can do the same things as Vega2 does for Extension:Graph. It is also better considering this at this point in time, rather than later, as Extension:Graph graphs are going to have to be updated by users anyway, regardless of whether WDQS graphs get used or Extension:Graph continues being used.