Private repositories can only be used by the Git Actions runner for that repository. For a monorepo, this works fine. If you have any semblance of microservices

Private repositories can only be used by the Git Actions runner for that repository. For a monorepo, this works fine. If you have any semblance of microservices in their own repos, orchestrating CI/CD and other build/artifact processes is a nightmare. Internal repositories allow the Git Actions runner access from any other private repository, meaning you can have one repository for all of your git actions that can be neatly called from any other repository (private or public) in the org.