The Microsoft GitHub requirement is the only reason that I do not contribute to NixPkgs except by sending a mail to a maintainer sometimes. Everything I package stays in my own flakes. If a community arose that hosts its own repo or is hosted at e.g. CodeBerg, I would contribute.
This has been a tough one to figure out. I do not think there is a great answer here. GitHub has a large network of people and the barrier to contributing there is fairly low. Cost is also subsidized greatly by GitHub. Nixpkgs being one of the largest and most active repositories on the entire platform would certainly strain any self-hosted or otherwise unprepared service. However, the benefits of a FOSS git forge with commitments to federation and values similar to this project also exist. Perhaps the answer here is to begin on GitHub to ease initial contributions and concerns over cost and to later transition to something like Codeberg.
Migrating off of GitHub once established is very hard in practice. That is why so many projects have stayed there. But asking people to make a Microsoft GitHub account when your Goal 1. is 'Independent' starts the project off with not following its own goals.
People might be hesitant to open an account at the hoster of the aux.computer infrastructure, so aux.computer could offer the option of logging in with a Microsoft GitHub account.
The Linux kernel, GNOME, KDE, Debian, Blender and more host they own forge. It's not a very heavy service. Running aux.computer infrastructure on aux.computer OS is a good showcase of the project.
Nixpkgs used to live outside GitHub. Migration to GitHub massively increased incoming contributions. Frankly, I don't think migrating away or choosing not to use it would be worth it.
