So, what can I do to give dragons an advantage that will possibly shine through no matter what? Which part of them have I been neglecting while trying to figure out how they fly? Yes, their breath weapon.
You see, my dragons don't breathe fire, they cast spells through their mouth (kinda like sorcerers in Dorohedoro, though they used their fingers there). This "magic" usually takes the form of greyish smoke, which is actually a swarm of micromachines under the dragon's control.
Micromachines doing stuff is considered magic here.
There are many types of micromachines that a dragon's body can produce. Some alter their optical properties to create illusions, others can act as disinfectants or deposit onto wounds, creating an artificial clot. And most importantly, they can carry strong oxidizers, toxins, or medicine.
This swarm lives in a symbiotic relationship with the dragon, using up some of their resources and life force (i.e: chemical energy, usually stored in fat and glucose) to power itself and replenish its numbers, never so much that it would kill the dragon.
In the setting, dragons are meant to be the masters of magic. Like, some of their powers can't even be replicated by humans, or at least their version would be very inefficient and lack certain features. Keep in mind, humans also have magical smoke, though that has to work off of that human's life force.
Dragons themselves are about as large as bigger horses (170 cm at the shoulders), and they can live for thousands of years. They're as intelligent as humans and while their scales can resist non-AP rifle rounds, that's about all their special biological features.
So, why are dragons, on average, more adept at using magic and why can't their spells be replicated by humans?