I want to see all this data for all of the forks that are relatively close together from a single pane of glass. This would make collaborating and uplifting code back to the main branch much easier for small free software projects.
I like to self-host, but I don't want to be sysadmin to a public service, and deal with account deletion, password resets, ...
Merging your patch even comes built-in with Git. The place hosting your Git repo doesn't need anything special to support this. You email the author, they merge your patch and then git push.
Some other federation method through centralized platforms like Github would have to be bolted on to git, email is just the built-in and very much intended method that already exists.
A "merge request" or "pull request" is a specificb thing on those platforms (GitHub/GitLab/Gitea/...) and are definitely not federated.
In the same way, Twitter is not federated just because it runs on phones where you could send your message via SMS instead. That makes no sense. Even if SMS is built into your mobile text editor.
Edit: Better link