I agree with the general thesis but I find the title a bit irksome.

He isn't even considering Lightning; he also isn't considering much nuance in the term 'cash' (which can thought of 'without counterparty risk', see how banks use the term), but anyway it is clarified as 'medium of exchange' later in the article.

There are plenty of us out here who are not only advocating 'muh digital gold' or even worse 'just borrow against it' (agreed, this is nightmarishly risky).