My personal "resume" side projects are hosted on GitHub, and my current company mirrors its open source stuff there also. But in neither case is GitHub really being used as a team collaboration tool. Also, we're not paying a dime since all repos are public.
It's basically a social networking site.
For real work, every company I've worked for in the past 5-10 years has used Atlassian tooling, either cloud-based or self-hosted. I have plenty of complaints about Bitbucket, but Atlassian OWNS the enterprise. And quite frankly, although it lacks GitHub's network effect for open-source projects... a lot of people prefer Bitbucket's interface, tooling, and pricing model for corporate team development (i.e. the situation for most PAYING users).
It's basically a social networking site.
For real work, every company I've worked for in the past 5-10 years has used Atlassian tooling, either cloud-based or self-hosted. I have plenty of complaints about Bitbucket, but Atlassian OWNS the enterprise. And quite frankly, although it lacks GitHub's network effect for open-source projects... a lot of people prefer Bitbucket's interface, tooling, and pricing model for corporate team development (i.e. the situation for most PAYING users).