There is a lot offered on the enterprise side. My company uses GH Actions for CI/CD, uses GitHub for OAUTH, it hosts our git LFS server, and it's where the slop lovers in the executive and management offices get their copilot fix. That doesn't cover half of it really, but it's a lot more than a git forge. I despise it nonetheless and think all of these use cases have better tools available

For an honest answer, from an Open Source perspective, it's mostly auth, profiles, and discoverability.

Presuming I have a GitHub account, when I encounter a library or tool or something that's hosted on GitHub that means I can fork it, make issues, comment on issues, make pull requests from my fork to upstream tied to issues, and generally have seamless interaction with any and all software on GitHub.

Or, if I have my account added to a project, then I can also merge PRs and push to master and be a maintainer of that software without any friction.

When I see that software is hosted on KDE's thing it's like "Ugh". I have to login to that, and create a profile for that, and then figure out how tickets work there, and how do I contribute to that. It's enough to just not, most of the time. And maybe I do that for kdenlive. Then I have a bug for Gimp. Okay, what the heck do they use? Is that another login? How do I contribute over there? Is registration even open? Okay guix, oh boy a mailing list. Do I want to subscribe to a dev mailing list just to submit a 2 line patch? I think I'll just not... I'm sure someone else will fix it eventually......

So besides all that, some people like their GitHub profile, and like that people can see all the things they've contributed to from one spot. That's why it's often linked on resumes, but beyond that there's also a kind of cultural cachet to having a diverse and positive profile, should someone look. If someone is a maintainer of a repo with a lot of stars, that might tell you they're "important" even if you don't know why. Because maybe you're a JS programmer, but this person seems to be big in the Java community, because they seem to maintain a few high profile java libraries.

And then lastly, it's sometimes useful as a shortcut in searching. "Source code" is kind of a useless term for searching, so if I search "ruby Ledger file library" I'm more likely to get some docs or a rubygems page, but if I search "ruby Ledger file GitHub" I'm probably going to get what I actually want, which is a readme and a git uri I can clone and play around with. Or a web view of the source I can search through to debug something without cloning. At least assuming that is what I want, it depends on what my goals are, but it's useful often enough that I do it sometimes as a way of jumping to the source part.

I'm typically anti-centralization, and anti-microsoft, and if we all move away from GitHub I'm sure I'll live, but this is why I like it despite its problems. And sometimes I want a webview of file contents, with search, without cloning, so sue me 😛