Very mixed feelings on GitHub's recent approaches to security. Tighter security measures are great, but deprecating password authentication on git operations seems obtuse to me. What if I want to push a change from a machine that's not mine and doesn't have my registered SSH key on it? I don't have a Yubikey or anything similar nor do I intend to get one in the foreseeable future.
That's a super optimistic viewpoint. Handling that kind of stuff is actually a pretty challenging technical problem. Reddit themselves wrote a nice technical blog post about the how they built r/place and the challenges associated with it. Dealing with synchronization issues across federated instances makes the problem quite a bit more difficult.