There’s something not only convenient but very compelling about putting all your work on one service rather than strew about several “profile” web sites. This is particularly true now that I maintain my Zettelkasten repos there. When someone discovers you, they discover all of you in a way that they can both search and follow (yes there’s an RSS commit feed for those who want it). And yes, Google prioritizes content found on GitHub as well as includes it in any searching. All this comes for free just because you chose to host on GitHub instead of managing some other extra web site you might have to SEO promote in some way to even be seen by anything else.