Let me repeat a question that stayed unanswered in the comments of the Gitea welcome blog entry:
How do you deal with Gogs changes since the fork? Do you review and merge them?
(P.S. I found out about Gitea by the FSFE now using it.)
Most of the time, no. Sometimes we cherry-pick small bugfixes, but most of the time, we are separate.
So the feature set probably has quite diverged already. What (besides the higher bus factor) are key advantages of Gitea nowadays?
From what I can remember: