Choice and flexibility
GitLab CE/EE can be installed on physical servers, virtualized servers (dedicated or shared), purpose-built appliances and virtualized appliances. These aren't available with hosted solutions. Likewise, most on-premises servers can be deployed on a variety of operating systems and there's more choice of on-premises solutions in general.
Containing your company's IP behind the company's firewall gives you protection from unauthorized access. Learn from the lessons of Code Space.
GitLab can integrate with Authentication and Authorization (LDAP / AD) mechanisms, multiple 3rd party services, CI/CD, and other tools such as ALM, PLM, Agile and Automation tools.
Take control of maintenance downtime, don't be at the mercy of your hosting provider. Control how and where your code is backed up and stored.
Getting your IP back from cloud vendors that store data in proprietary formats can be a costly and lengthy process. No such trouble with GitLab CE/EE.
In good company
GitLab is the most adopted on-premises solution for developer collaboration, deployed at over 100,000 organizations worldwide.