Exactly. These sorts of things only have value as collectors items and can't really be good as a physical "cash" version of bitcoin.

Valaurum (or my Shire Silver) does work as a physical cash-like thing, but doesn't work online. Bitcoin works fantastic online, but doesn't work offline.

Once you separate bitcoin from online you lose the safety that is provided, just like if you try to make gold into a digital currency you lose the safety of physically holding it. Its all about having actual control over the currency.