What other on premise lifecycle development solutions are there?
TFS/VSTS/DevOps (Microsoft)
IBM, Atlassian, CA, GitHub, Microsoft, Micro Focus, Perforce, to name a few. Even if you believe GitLab's 100,000 number, Atlassian claims more than that and they're a public company so less likely to fudge the numbers.
Most of Atlassian customers are using their cloud solutions at this point.