Well, the argument holds for any big system. It is better to keep things modular and simple, so anybody can work on each of the components (in parallel), and improve each of the components, and replace them at will.
Also keep in mind that protocols are much more important than the actual code implementing them (see git for a good example!)
I guess I'm still not following.
If I sync a git repo from random location, I have the files to make that package. However none of the documents that aren't explicitly in the git repo are provided. With Git[hub/lab/...], this is metadata outside of the repo. Ideally, I want and need that as well. If there's an issue, I can research it quickly and see if it applies to me... Or if I'm a maintainer, I can make a solution offline and then merge it when online.
I understand that it may not be the perfect tool to include everything... but it does seem to fit the bill. Fossil does seem to do this correctly. I'll have to look into it.
Could you elaborate?
I think I've heard the argument before, but I don't really see how. These outages show up again and again, partly because people cannot access the project issues.