Comment by rvz

Short answer: Absolutely yes. If you can setup a website using Docker, you can do the same with a Git server on-premise. Many companies have done this without Github for years.

Why you ask? You have total control over the stack, CI, etc and some orgs have in-house sys-admins or IT department to do all the work independent of a third party like GitHub. Maybe you should ask the Linux Kernel Project, WebKit, OpenBSD, Mozilla Firefox and even RedoxOS maintainers about why they self-host their projects which some even have mirrors on GitHub.

On another note I keep seeing this over on some repositories and now because it is 'private' I don't even think it remotely makes sense or is a good idea to even use GitHub to backup private keys even if the repository is 'private'. As long as it is on someone else's server, you're not in control.