But,github wanted to make this process easier for the people,hence they included issues,fork and PR model. It was easily done with intuitive interface without necessity of email for workflow, but if you have asked me, i would have issues,wiki,etc. integrated within repo just like Fossil VCS.
p2p is cool but not solution to this . gitea/gitlab/etc. already provide importing of issues with repos and if not,they must provide that feature.