Ask HN: Gitlab, Atlassian, GitHub, etc – which one?

If you were starting a software company today, and had no technical debt from using legacy technologies in place, what software stack would you use to run the software development company?

Capabilties such as:

- VCS, - Issue tracking, - project management, - CI/CD, - chat, - maybe even HelpDesk - etc?

Gitlab & Atlassian seem interesting because they both have the full stack of capabilities (VCS, Issue Tracking, Project Boards, CI/CD, chat, etc).

Yet Atlassian is a bit "old" so don't know if that's good or bad.

Then there's Github, but it's lacking CI/CD and a number of other features.

If you had a clean slate, what vendor stack would you use and why to run the software development and deployment of your product?