It depends on how you use git. My primary working repositories are all local, and not readable or writable by anyone else (nor should they ever be). I push my working branches to GitHub regularly, so others can pull from them. My collaborators on various projects do the same thing. I could push anywhere that's appropriate. A corporate or publicly-accessible Forgejo instance, GitLab, or even just a folder on my web server.
In my naivete I thought this sort of local repo, public repo split is how git was designed to work. Pull requests could take any form, really, provided commit messages meet your requirements (this commit closes issue #foo), and it's simply a matter of git pull. Sure I have to add remotes to my local git repo, and possibly create local branches to review the pull request commits, but that's not too hard. git gui's like gitg come in handy for navigating numerous branches and remotes. The author could have done that in the time it took him to write a complaint about GitHub. And like I said, github actions can be made to run locally in each collaborator's local repo.
git is decentralized. Development need not stop when GitHub has problems, and it should be trivial to move off of GitHub if that was necessary. Of course, maybe I just use git wrong. And sure I can understand that corporate development doesn't really mesh that well with git's distributed model, hence the use of GitHub as a crutch.