In particular, this blog post is a direct response to
forge-netForgeFed (formerly known as GitPub). They want to federate and decentralize git using ActivityPub, the same technology leveraged by Mastodon and PeerTube. But get this: git is already federated and decentralized!
These articles ignore the main reasons people use github (or any git host), things like:
These are the things an activitypub git host would help to decentralize. Yes git has some helper tools around being able to send your commits over email, but it replaces none of the features above.