Unfortunately, github is 50% git, 50% proprietary code that you don't control and can't neatly export your data for other platforms. All these git hosts are walled Gardens. It's a sad state of affairs but not really limited to git (Gmail walled Garden despite email standard, messaging apps, etc).
Github has some great management tools for reviewing code and integrating with various integrations. But so does Gitlab, Bitbucket... and I'm sure there are more. They aren't 1 for 1 replacements, but they do exist. I'd personally recommend against using a ton of integrations that tightly bound you to any service.
