Long story short: Gogs was slow in committing pull requests. The maintainer says it's because he has specific standards, the community sees it as just slowness. Anyway Gogs was forked into a new version that is supposed to be more active and well maintained.
Well the forking lit a fire under the ass of the Gogs maintainer and he has since become much more active than he was. For a month there there was reason to switch to Gitea as it was adding features that Gogs did not have at a rapid pace, but Gogs is now mostly caught up and there is reason to prefer it. I personally would go with Gogs. 1 passionate person > design by committee of people with shared low responsibility.
From gogs to gitea all metadata has been taken over (db was identical then). -- For gitea to gogs I read that the two projects have diverted. As I could afford to loose metadata of my not too many projects, I went back to gogs ditching and recreating everything (wrong switching decisions should be punished, don't they;).