For Codeberg, they don't allow closed-source* projects. You of course have Forgejo (which is what Codeberg utilises), and many open-source developers have been moving to it. I've also heard some projects switching over to GitLab as well, which is corporate-owned, but I believe has a self-hosted option that gives people a little more control. But for many people, GitHub works fine as it is and don't want the hassle of transferring their projects, commit history, issues, etc. over.