This is an interesting question as there are many things that I can say that would fit this question. Perhaps it is the escapism of being a magistical being from the prison of reality? A yearning to break free of mortality and depending on one's choice of mythos they base on, enforce morality or forsake them? Perhaps the desire for power and wisdom and something relatable as well, something many may seek in the sort time they have before they expire. Wealth, power, wisdom, dominance. All of these play factors into the fantasy and why many would spiritually associate with one instead of their innate humanity. Why be an ape lacking in fur that only thrives from it's cunning and intellect when there's so much more that could have been? This isn't something that is isolated either, every culture around the world has developed their own form of a draconic being be they protectors, destroyers, or just feral beasts that maurade across the kingdoms of yore. I mean sure, I can say being big enough to eat folks is my favorite aspect, but that is just an oversimplification of a much more philosophical and spiritual ideology that can be poised to ask why anyone wants to be anything else. At the end of the day however, our online persona's are for the most part an escapist fantasy, and even a reflection of one own's ideas and beliefs. Some just prefer strength, power, and wealth due to a lack of it in life, others may seek kinship, loyalty, and a sense of purpose as another.

To summarize this one up, it's much more easier to say that my favorite aspect of being one is not only the sheer flexibility, but also the iconography that predates the fandom itself. Even back in medieval and ancient times nations flew dragons in banners and coats of arms across the globe, a sign of power, regalty, and even dominance but also a sign of wisdom and prosoperity. All these elements coming together to form a being of perfection, of everything we all strive for even though many can only hope to achieve in life, yet never is it impossible to reach and always remains as a life path to follow.