Unfortunately a hosted GitLab is downable when GitLab itself goes down. Same for all the other hosted source control and CI systems. Given that many companies

Unfortunately a hosted GitLab is downable when GitLab itself goes down. Same for all the other hosted source control and CI systems. Given that many companies now tie their entire deployment process into their source control and CI/CD systems that means you really are reduced to exchanging patch files. For any non-trivial change in a large system that quickly becomes impractical and so development slows to a crawl or everyone literally gives up and goes to the pub.