To stray outside the lines with some meta-commentary: it's nice to get a well thought out response instead of the sort of kneejerk rooting-for-my-home team that's on display in the wasteland of intellectual dishonesty in the comments below.
For the most part it's the same workflow. Also, if it's a trivial change (like fixing/appending something in documentation) you don't even need to leave the browser.
Discovery is another issue... it's far more easy to use Github semi-socially than most other platforms. Something I both love and hate is that GH doesn't have a direct message functionality. On the one hand, I wouldn't want to be bothered with a ton of end user emails for the same issues over and over... on another, after you've waited a week for a bug fixing PR, it's not fun either.
As much as I hate centralization, especially when the central entity is a for-profit corporation running closed software, often that ends up giving you a standardized experience that makes things easier. "Easier" doesn't have to mean fewer steps; I agree that the GitHub workflow you describe isn't simpler, but if you've done it a few times, it's mechanical and you don't need to think about it. GH even provides a command-line tool[0] that lets you avoid most of the click-around-on-website steps.
[0] https://github.com/github/hub