Perhaps it's because I've never actually joined an OSS project (because I am not a programmer), but I have never seen evidence that the tools of doing so (git etc) or the culture —organizational and community—accommodate contributions on the level of architecture, UX, design.

"If you want that feature, jump in and help build it!" is
*ableist* discrimination because the insinuation is "you gotta code to contribute"
Well lemme tell ya… I have ~20yrs experience designing software. I could do a lot for you if you let me contribute with briefs, diagrams

I don't mean to rant about it. What I do want is to figure out a way that people like me can contribute and see that reflected in the toolsets of collaborative software making.
Where are the "architecture", "UX", "Design", "PM" sections on GitHub projects?