FWIW, this decision was not taken lightly (see
https://phabricator.wikimedia.org/T211881 for some of the history) and we are still hoping to re-enable server-side graph rendering in the future, but any such rendering would be with a totally new service (
https://phabricator.wikimedia.org/T249419), as maintaining the previous Graphoid service was untenable. All current graphs can be retrieved as PNGs from the
REST API if wikis prefer to use static images instead. (Examine current page sources to see the API calls.)