Gittea is great but it doesn't replace GHA, only the rest of GitHub.
Gitea + Woodpecker CI works pretty nicely.
They've actually just rolled out an early version of Gitea Actions in the most recent release, which are mostly compatible with GitHub actions.
https://blog.gitea.io/2023/03/gitea-1.19.0-is-released/#-git...
That is indeed great news!
It is also apparent that GitHub Actions has chronically been struggling to operate normally for at least a single month for years.
There is no question that GitHub has been more unreliable than if you were to use a self-hosted GitLab or Gittea instance yourself as I said before [1].
[0] https://news.ycombinator.com/item?id=35325850
[1] https://news.ycombinator.com/item?id=22867803