There are already a bunch of great posts arguing against requiring GitHub contributions as part of the hiring process. I particularly recommend The Ethics of Unpaid Labor and the OSS Community and Why GitHub is Not Your CV. While both of those posts give excellent reasons to reconsider asking for open source contributions when hiring, my take here isn't about why it is ethically dubious to require open source contributions or why GitHub isn't great for showcasing your projects.Instead, this post is about why GitHub profiles just aren't all that useful when looking to hire developers.
In 20 years of working and hundreds of interviews and phone screens, I've rarely, if ever, looked at a candidate's GitHub.