You still have a single, centralized mailing list server. That's what you should be comparing to GitHub -- not the individual mail servers for each user. If yo

You still have a single, centralized mailing list server. That's what you should be comparing to GitHub -- not the individual mail servers for each user. If your mailing list server goes down, no one can use the mailing list. Taking it a step further, if its data is lost, everyone has to re-subscribe. On top of that, you have a mailing list archive. If that's down, or not operating, you've made thing even less open, because now any non-subscribers can't even read what's going on, and if they do subscribe, they only get to see new messages. Existing long-time subscribers have an archive, sure, but it's very possible no one user has a complete archive, and it's a certainty that most users don't. Someone can run a redundant mailing list archive server, but then someone can also mirror the GitHub repository, PRs and issues. --- That said, the mailing list server and archive are likely simpler to run, less likely to go down, and easier to move somewhere else. Transferring from github.com to something else is going to be painful, and I suspect most FOSS authors simply don't think about it or see the ease and benefits of using it as outweighing the risk. Companies should look at that risk much more closely, but ultimately it's the same situation as if they decide not to have fire insurance: if their building burns down, they're SOL, but that was the decision they made.