It mystifies me how people think Github is important to use for the community. Stars are often cited as a primary reason, presumably so projects can list their star counts on their web pages.
To me, the choice of Git repo should be one of the more portable aspects of a project. I know there are hideous lock-in mechanisms like issue lists and wiki discussions, but hopefully someone will standardise them one day into Git objects.
Regarding the issues, there are some projects like git-bug https://github.com/MichaelMure/git-bug trying to embed these sorts of meta-work into git.