Gold, silver, and other precious metals and gems have intrinsic value that can not be erased by government or corporation and has a history of being valuable, what, more than ten thousand years? If all forms of government vanished overnight and we all regressed to grunting beasts coming out of trees, we would probably *still* give value to gold and silver and other pretty, shiny, rare items.
The problem with currency is that it is only representative of an agreed-upon make-believe value, but it does benefit from being something you can hold and possess and control (physically), if not having any influence over its value which isn't tied to anything "hard".
The problem with "cashless" currency is that it is only representative of an agreed-upon make-believe value *and* is only allotted to you at the whim of technological stability, human accountability, and government. It is different from hard cash in that hard cash that is in your hand does not accidentally get sent to the wrong account, seized (unless physically by force), deleted, siphoned, etc.
Of course, it's an ideal dream to have all of your money in life entirely stable and secure sitting on a server somewhere digitally that can not be stolen, can't be hacked, can't be lost, can't be seized, etc . . . but until someone discovers something much better than anything we have today, it has all the negative aspects of all the forms of currency/trade and pretty much none of the benefits.
PS: I'm not saying to become a Glenn Beck nutjob and start filling your pantry with gold coins -- just using it as an example of a form of established currency and valuable items dating back pretty much since the dawn of man's history to reference off of.