When I tapped the side menu, machine learning had a grey background so I assumed I was on the "machine learning" page already, so I didn't click it. I now see it reveals a long submenu of the illustrations.

I agree with others that are saying it's too hidden away!

I'd just add a list of them to the index page I think.

I've tapped every conceivable place on the page on mobile and I can't find a list of illustrations? Or any single illustration?

Is my brain broken?

All metrics are stacked massively in favour of first level citations - many entirely ignore second level and beyond. For example, a paper's "cited by" count is its most prominent metric of influence/importance, and is a count of how many papers directly cite it.

I don't know this particular beef, but it sounds like citing GRU and not LSTM is a potential sleight/insult here. Exactly the kind of thing you see in petty academic rivalries. You're explicitly deciding who you're crediting with the key innovations you're building from, and you know that most people aren't chasing every sub reference of every citation.