I used to write quick blog posts some years ago, and post on social media often, but I never wrote something I considered a professional article because of hesitations like you're expressing: it needs to be 'uniquely insightful', it needs to be 'applicably useful', it needs to be 'well written.'

Then one day I was like 'screw it' and started posting to Medium. I've written ~7 things so far, quick articles, tutorials, or reposting a slideshow I made for other reasons, and they have all been read and been provided recommendations/likes/shares/feedback to some degree. In terms of career growth, it's not been an instant magical boost, but it's more like 'networking' in that it enables people to connect with you, laying groundwork for collaboration in the future.

The thing is, certain people you can reach at a certain time are a unique factor in what drives interest in your writing. Maybe someone didn't see the other github page, but they saw yours. Give it a shot.