Github, as I know it, is used for open source software development. This research is very different from software development in that there are many experiments done, many texts collected many attempts to arrive at good theories etc.
I agree that some organizing will definitely help as I often can not find pictures, video's etc that I have done earlier. I try to keep things organized on my PC which is hard enough already so my question is "how is github going to help me?"
BTW I also have many things on my gdrive, for example: Tesla correspondence
BTW2: this Tesla correspondence was a community project started by me to get all this stuff transcribed. It is largely done, but still needs verification, formatting and combining into pdfs.