With GitLab you can actually go from idea all the way to production, quickly and easily. You don't need to set up and use external integrations and have a powerful issue tracker, CI/CD, wikis, and much more.
For instance, to deploy and monitor a simple app, all you have to do is enable AutoDevops in your project and GitLab will take care of the rest. It's very powerful, see the video here: about.gitlab.com/2017/09/22/gitlab-10-0-released
If you still want to use your own tools, like JIRA, GitLab integrates really well with them. And lastly, GitLab is improving every single month with large jumps. We just renewed our navigation and it's now super easy and quick to jump between your projects and groups.