Wasn't Alex chapel that started this? https://www.youtube.com/watch?v=CHFK5sY8ToE
I believe Zack started Gridfinity, but I don’t know who the very first designer was that built a modular storage system for the 3D printing community.
I’ll say this - the Gridfinity community is, from my POV, unique in how they’ve taken this and really run with it as a crowd sourced concept.