> Another, admittedly extreme, case was Ludwig Wittgenstein getting his PhD from Trinity College. He had already written the Tractatus Logico-Philosophicus on his own, then basically showed up and presented it as his dissertation, defended it, mocked his friend Bertrand Russel during defense and got the PhD.

> What's crazy to me is that if Wittgenstein was alive today he would not be able to achieve this anywhere.

Not so. Cambridge still does it, e.g. https://en.wikipedia.org/wiki/Aubrey_de_Grey in 2000.