I don't think the article makes a case to shoehorn git in each and every usecase that goes beyond tracking changes to project files.
For example, both git-issue and git-bug are an awkward interface to track issues whose main selling point is being git-based, which is not much to start with. They are focused on the persistence layer used to store ticket info when that's both a solved problem and irrelevant to the problem domain. To top that off, Git's main selling points are its distributed nature and ease to branch off/merge changes, which are not relevant for this problem domain, and the main value of issue tracking is to track the overall progress of a project and audit changes, and these tools offer a worse user experience than any of the tools they supposedly try to replace.
Given there are plenty of outstanding free tools that do a far better job at this in their free tier than any git-based alternative, I fail to see the real-world value of these projects.
If anyone is actually interested in a solution that bundles up revision control, issue tracking, and project management, they are far better off just onboarding onto tools such as Fossil.