When git replaced SVN, it was so empowering that I, as an individual, was able to use the full maintainer workflow without the blessing of a maintainer, privately by default.
Before git, we saved the output of "svn diff" into a .patch file for tracking personal changes. When submitting a patch, the maintainer had to write a commit message for you. With some luck, you even got credited. For sharing a sensible feature-branch, you had to become a maintainer with full access. This higher bar has advantages (it tends to create more full-access maintainers, for one). However, it sends this message: "Yes open source, but you are not one of us."
Yes, fossil has this great feature of showing "what was everyone up to after release X". I miss that in git. (Closest workaround: git fetch --all && gitk --all.) But if "everyone" means just the core devs, then I'm out.
I've been using Fossil for years and TBH i don't see that "closed team" culture you speak of (though i also have almost all of my projects as "open source, not open contribution").
Fossil is a distributed version control and in fact it is "more" distributed than git if you consider that people tend to tie it with centralized services like GitHub to get more than just the VCS part. A Fossil repository contains not only the versioned files, but also a wiki, tickets/bugtracker, forum, chat room, blog/technotes - even the theme is part of it. And since it is a decentralized system, all of it are cloned when you clone the repository.
AFAIK the only limitation (hasn't really tried it myself since i only use it solo) is that for security cloned users aren't "fully" cloned so you'd need to make new users in the cloned repository - you can use the same username though (but in commits, history, etc it'll appear as different users). It'd be useful if "user" and "identity" could be distinguished so that you can have the tool know that two usernames are really about the same person.
Also Fossil works pretty much everywhere - a local server, as a FastCGI server, as a plain old CGI "script", you can even have it as a "CGI interpreter" for ".fossil" files (the repository files - the entire repository is stored in a single SQLite database file) which makes it usable with many shared web hosting services without needing root or even shell access. In a way that is the most decentralized you can go :-P.
The GitHub blurb makes no sense. Even if N developers standardize their workflow on using a couple of remote repos to exchange work, that does not make the underlying system less distributed/more centralized.
> A Fossil repository contains not only the versioned files, but also a wiki, tickets/bugtracker, forum, chat room, blog/technotes - even the theme is part of it.
That sounds like a major design faux pas. It makes zero sense to tie a chat room/blog/e-mail client/alarm clock to a source code repository.
I think you need to reconsider your senses if you can't see the tie between the two :-P. The "more distributed" part was exactly because of Fossil providing that additional functionality GitHub provides in a decentralized form.
I use fossil for my personal projects and git for work.