Which is slightly odd, considering that in hyperinflation, paper cash was losing value just as fast as intangible money.

However, the privacy aspect makes cash usage understandable. But it is somewhat inconvenient sometimes - for example, you generally have to be prepared to pay taxis by cash, not bank/credit card as in Nordics.

And there is a culture of hiding assets from the state. I remember a while back the German police where regularly catching pensioners driving to Luxembourg to smuggle large amounts of euros which they did not want to pay tax on.

A cashier's check is effectively a cash equivalent - it's a check guaranteed by the bank, wherein they basically freeze the funds in your account at the time you write the check. The only real purpose of it is to save people from carrying around huge amounts of cash. So that doesn't really answer his question.