That is like saying that beer is a currency because there are beer dealers all over the place.

Sort of. I suppose there is some secondary market in beer. Near a college, maybe?

You can readily hock a car for money, so that's a few levels closer to being a currency. You can sell used media.

But there are people in the business of buying and selling gold for the sole purpose of readily converting it to currency and vica versa so that gold can be used as an alternative to paper currency managed by a nation's central bank. That's almost all that gold is used for, and that's what dealers in gold coin and gold bars are in business to enable.

Except that in practice, weights of gold are not used as a medium of exchange in almost every market in the world. Gold may be used as a store of value, but so can land, buildings, collector's items, etc. One of the defining characteristics of currency is its use as a medium of exchange in a market.