Earlier quoted context omitted.
Git makes it easy to make copies, but its nature of having one designated "origin" remote per repository that serves as upstream source of truth (on platforms like github also across forks) makes it not really federated/decentralized the way Mastodon et al. are. And I don't reaaally see how this tool solves that problem. Or any of the other problems you mentioned. But that said, Mastodon/ActivityPub don't really feel…
> one designated "origin" remote Git is not limited to a single remote. The default remote is called "origin" but there's nothing particularly special about it.
To be more precise, git clone adds the origin cloned from as a remote named "origin", unless you override this with a configuration setting or the -o option.
The default is no remotes at all.