I've used sr.ht for some time and it's not that hard to work with e-mail flow. It's still not as easy (the main problem is setting up SMTP settings but that's done once). From my perspective most of the issues with git that GH solves is tooling, that same could be achieved with ML.
That said, having worked with git internals and models of repo access I'm pretty sure GH introduced forks to work-around the issues with repository control. Conceptually there is no need for forks, one could push to private branches of the target repo directly. Unfortunately git doesn't have tools for per-branch level controls directly. More details in https://github.com/rescrv/gitswitch
That said, having worked with git internals and models of repo access I'm pretty sure GH introduced forks to work-around the issues with repository control. Conceptually there is no need for forks, one could push to private branches of the target repo directly. Unfortunately git doesn't have tools for per-branch level controls directly. More details in https://github.com/rescrv/gitswitch