FWIW, this project made its first release in 2018. =) It's been posted to HN several times, though under its previous project URL, https://github.com/MichaelMure/git-bug (see https://news.ycombinator.com/from?site=github.com/michaelmur...)
you aren't alone! linus thinks we need this, too:
I had the same idea for a talk a long time ago the result is https://git.esy.fun/yogsototh/gpm
I never used it seriously, but the concepts are easy enough to grasp.
Have a separate dedicated branch that contains all the metadata of your project. Like issues, todo-list, review comments, etc...
Hopefully, something decentralised like this could become more popular maybe.
This is wildly exciting.