As a strong Free Software supporter on HN that uses Github I'll take a shot.
I use Github to publicly host my projects. I use github as I want them as public as possible and that is where all the people are.. I.E. it has the lowest friction for others. The tradeoff is a bit of extra work on yourself to make sure you keep the 'git' part of your repo the central thing. Use the hosting as extras appropriately, but don't rely on them. All relevant context, reasoning, etc. needs to be in the git commit messages. The git repo should stand alone and tell the complete story.
IMO following this simple rule you can keep your project git repo whereever is easiest for the users without lockin. Github's added features over basic git hosting are decent but none of them are irreplaceable if you keep your repo up properly.
Hosting your projects on Github is not an issue. The issue is hosting your projects only on Github, or depending on it for anything other than visibility.
I have my own gitea for private projects, but the open source one I host primarily on Gitlab. It's where I set up the CI, it's where I have pages, docs, etc. I do have a mirror on Github, but on the "Contributing" section from the README I make it clear where I prefer to receive PRs.
If you are not expecting other people to collaborate with you and if you do the same local hosting for your CI and issue tracking, etc... Fine, I guess?
I only worry about collaboration via github. I don't need an issue tracker or CI on my local repo. Github issues and PRs are discussions, not records. That's the point of the self contained repo commit messages.
You seem to be under the impression that OP was criticizing your approach. Your usage of Github is not representative of the majority of cases. You are only in Github for visibility, and the commit history/repo hosting are already distributed, which is fine. You can move away at any time.
What OP was criticizing was these larger FOSS projects who don't seem to mind that they are doing all their work on a closed platform, and that they have a lot to lose if Github decides to pull the rug from under them.
I went off a bit into more personal cases in the thread. But my original post was aimed at other/larger projects. If they maintained a proper git repo and used the platform tools as secondary tools (eg. discussion oriented instead of record oriented) then they wouldn't be locked into Github. I agree that a bunch of ones don't do it correctly and put the context that should be in the repo/messages into the PRs or issues. That is a mistake. But switching from Github won't help that... they'll just do the same thing elsewhere and lock themselves into that site or tool (ie. lockin doesn't require a service, just tools that do more than manage the repo).
I use Github to publicly host my projects. I use github as I want them as public as possible and that is where all the people are.. I.E. it has the lowest friction for others. The tradeoff is a bit of extra work on yourself to make sure you keep the 'git' part of your repo the central thing. Use the hosting as extras appropriately, but don't rely on them. All relevant context, reasoning, etc. needs to be in the git commit messages. The git repo should stand alone and tell the complete story.
IMO following this simple rule you can keep your project git repo whereever is easiest for the users without lockin. Github's added features over basic git hosting are decent but none of them are irreplaceable if you keep your repo up properly.