Free CI is what really is going to keep many on GitHub (Actions). Codeberg has Woodpecker CI requires a FOSS application to get approval to use limited free tier. CircleCI has a free tier also but doesn't look like official documentation for integrating with Forgejo.

Being able to produce x86_64/arm64 builds for macOS, Linux, and Windows for free is a minimum start to get movement to another provider IMHO. GitHub already does this.