And then everybody clapped

I think those tropes were mostly accidents actually, in medieval times you’d slay a dragon because it was literally a demon from hell, like that’s literally where fire breath comes from, because their mouth is a direct portal to hell and opening it can unleash the fires of hell.

Tolkien is probably one of the first authors to portray the Dragon’s horde in a context of a sign of the Dragon’s immoral character, as opposed to an incidental that made for a good source of loot for the hero to get a cool new toy from, and even then that’s how most narratives involving dragon’s hordes treat the actual horde, the horde itself, given back to the people or not, is not especially relevant except for a few choice items which the hero takes a shining to and keeps, it’ll happen in D&D just cause.

“…and because they burn villages and homes, eat livestock and people. Do you really have to ask why we should kill the terrifying man eating beast?”