They're physical embodiements of human negative emotions. Greed, pride, gluttony, wrath. A dragon has all of them in spades. They hoard money because they are compelled to be extremely wealthy, but also find the fruits of human labour worthless so they don't bother to buy/have things built.
Dragons
Jose Green
Tyler Morales
So 100-300 °C ?
Owen Turner
Because dragons are ancient intelligent beings who desire power, and ostentatious wealth is often accompanied by power? That might be a neat explanation?
Eli Roberts
Because Fafnir.
Asher Reyes
Is that a golden dildo?
Kevin Allen
There are two ways you can take it:
1. Dragons have an incredible sense of taste and smell. They can tell the difference between metals easily. For them a hoard of gold fills their lair like incense. It soothes them and attracts mates from across the land.
2.Its not about the metal itself but the power and wealth it shows. It's not enough for a dragon to be rich, it needs to be richer than everyone around them. Everything needs to be in awe of its majesty and power. All creatures should be envious of its hoard and left grovelling before its might.
Joshua Lee
What about good dragons?
Ethan Rivera
Jose Richardson
Treasure attracts things, which means food. The dragon can lay in their cave, and victims will willingly come to them. Free food without effort.
Hunter Long
The gold attracts creatures who want gold to come to the dragon's lair to steal some, the dragon then eats these creatures. Thus the dragon gets a bunch of free food due to living in a massive pile of treasure. It still has to hunt obviously but free food is free food.