I wonder why they advertise the "platform"/implementation language so clearly (in this case Go). It shouldn't matter for the users? I get sceptical, as if the only reason they exist is to provide the same service but in a new implementation.
I've been using Gogs for personal use for a while. I love its speed and its simplicity.
That said, it's probably not a good fit for most businesses at this point. It's relatively new, and mostly maintained by a single developer, who spent the last summer on vacation.
He's very active when he's around, and almost always working on improving Gogs, but there's a lot of people with features requests (the issue that's always getting comments today is for opening pull requests across branches within a single repository -- i.e. not forking.)
Yes, because not everyone uses Docker yet. Some may never adopt it. So long as that remains a viable path, then the matter of deployment systems and complexity is relevant.