I’ve gotta say, the sheer amount of worldbuilding weight the origin dragon carries in these stories is kind of exhausting sometimes. It's like every series needs this uber-ancient, mystically vague progenitor to justify why dragons exist and why they’re magical. I think it works when it's done with some subtlety—like in the Pern books, where the origin of the fire-lizards and dragons is a slow-burn mystery tied to colonization and lost science. But a lot of newer fantasy just uses it as a quick lore dump to explain the magic system. It feels less important than the actual relationship between the human and dragon characters on the page.
That said, I do get why authors lean on it. It answers the 'why are there dragons?' question upfront, which lets them focus on the adventure. But honestly, I’m often more invested in a dragon’s personality and the immediate bond it forms than in some dusty, millennia-old backstory. The origin becomes crucial only if it directly threatens that bond, like if the magic is fading and the current dragons are the last.