You know, visual artists have an advantage over writers in that respect. If they want to depict a hoard, they can keep on painting golden coins or what have you. A writer has to, on one hand, convey the immensity of it, and a single phrase -- enormous piles of golden coins -- does not carry the subtext of lots and lots of stuff. You need more variety, perhaps a paragraph or two.
But once that's over with, there's occasion for world-building speculation about effects and consequences. In one thing, D&D was bang on the nail: the price list was grossly inflated from medieval times, as if there had been a gold rush, in order that the DMs did not have to chose between eking out the treasure and making their characters the richest people in the kingdoms before they hit third level. A treasure trove such as Smaug's would upend an economy.
To be sure, it might have some good effects. Medieval kings were notoriously short on money. (Nothing implausible about Don Giovanni de la Fortuna making the king a loan.) And the mere flow of money can help things along. After all, money was invented for a reason: to facilitate trade. There's a story by Poul Anderson where some fairy gold is dropped in a town's economy. It ends up in the hands of the man who received it originally, having done a lot of good by letting many characters disencumber themselves of an unwanted assets and obtain one that they wanted. To be sure, few writers depict a society with such a serious shortage of coins that trade is hampered.