Currently on https://wikimedia.biterg.io we only track Gerrit and Wikimedia Git activity.
Tracking Git activity (not: PRs and tasks) of GitHub repos which are related to Wikimedia would give us more complete developer activity statistics.
This is complicated by T109939 as AFAIK there is no way to identify repos on GitHub whose canonical home is on GitHub and which are not mirrored from Gerrit/Git to GitHub.
(For the records, I once upon a time tried a bunch of things in T163576 to investigate.)