I'm mostly familiar with gitlab, what does github provide for free above and beyond that? I like that I can run my gitlab pipeline on my machines and sync to a free gitlab instance. I like that I don't read about security vulnerabilities in gitlab pipelines nearly as often as github actions. I like gitlab issues as they are fairly minimal.
GitHub registry, GitHub actions and GitHub Codespaces are unlimited for public repos, in addition to all enterprise features.
That's without talking about nice to have features like GitHub Sponsors, the for you tab, the (arguably) more popular UI layout, It's simply a better platform for Open source projects