I would love to see Medium adjust their formatting to make it possible for something like Tables of Contents, or faithful rendering of notebooks that don't just rely on Github gists, but until then, I think it does a huge disservice to the actual information that technical/symbolic-math-including authors are trying to convey.
I'm generally allergic to tweaking things & general command-line bullshit but the whole process was surprisingly smooth. Readers don't have to deal with popup & tracker bullshit (except for youtube, who have endeavored to make it impossible to embed videos with issuing tracking cookies), and it feels nice to have much more control over what makes it into the final product.
For any quantitatively-oriented person, the quickest solution might be to write the article in LaTeX and host it on github.io, but other solutions are of course possible (e.g. MathJax and some other free web hosting).
For random matrice the author introduces what it means to be rotationally (O) invariant, but is what follow restricted to that? Also it is not too clear why the code is actually doing (creating the same ensemble) as what was talked about before.