the point doesn't matter, what matter is what the platform allows, github allows for organizations and membership access over a repo, removing the distributed aspect of a repo
whether it's on github or another git server not doesn't really change much, you have a myriad of repositories, each with their own restricted set of people with push access. Linux also has a restricted set of people with push access
So you're saying if we had several Oys it would be fine? That's still not "distributed", you just have a small group of people that need to closely agree on what should get in - and often work with some form of hierarchy