I have 121 repos on GitHub. A couple GitHub API versions ago, I built a custom viewer for just the public ones. Assuming you had the time or patience to dig through 121 repos to determine how I code in extraordinary detail, would you ever discover from GitHub my skills in motion graphics or visual arts?
I've also got skills in marketing and public speaking. You can't find any evidence of that on GitHub either. I've advocated the idea that GitHub makes resumés obsolete in the past, but I've come around to agree with the critical viewpoint:
I would argue that "in the age of GitHub, Stack Exchange, Coursera, Udacity, blogs, etc." the relevance of a concise and a well written resume is more important than ever.
This is a massive relief to me, of course, because I sell a video on how to write good resumés. Sorry to go there, but there's a fantastic testimonial.