True dragons, the first dragons, were born in the forging of the world. Created by the First, Ahl, as a gift for his beloved Second, Zho. As the primordial earth (having drawn Zho from himself to form the sky), Ahl used all the strength and glory of his ores and minerals, all the power and beauty of the swirling stars and celestial bodies in Zho's firmament. So did dragons come to be in the World of Orea.
These first were dubbed "the Children of Zho," the Elder Wyrms. Beings of gleaming beauty and elemental power. Massive in size and unparalleled in magic. The first dragons who would become known through the ages by their few remnant descendants, now called the Glimmariin by Man and Elf.
Once the Chaosbringer, Karos, was loosed upon the world, the corrupting influences of the Elder god of Evil and demons, and his chief servant in temptation and darkness, Djarthoon, the hearts of many of Zho's children were corroded and maligned, filled with malice, wrath, greed, and envy. These dragons -while still of frightful power- diminshed greatly from their original strength and lost the luster of their Glimmariin (Metallic) brethren. They became, to the peoples of Orea who consider such things, the Dwimmunduin (Chromatics).
Over time, several -even a majority- of dragonkind grew weary of Orea. The wars with the Titans. The proliferating mortal species endlessly irritating and trying to steal their riches, do them harm, beg for magic secrets. Many went behind the Veil, to explore and take solace among the stars of their beloved "father's" sky. Others passed away to seek out different realms -to Faerie, the Plane of Shadow, and other planes of existence. These are collectively known to the sages of draconic matters as the "Astraeliin" dragons (including Astral, Celestial and Infernal varieties).
There remains on Orea's main continent small numbers of most metallics and chromatic varieties known to players. It is unlikely for any group of players, however, to encounter multiple numbers of pretty much any type -other than Whites which are generally feral pack hunters when younger.
What inhabitants of Orea, however, are much more familiar with are the threats of draconic broods...the largely "mutated" or "malformed" draconic creatures that occur in the broods of true dragons. Wyverns, Behirs, Hydrae, Dracolisks, Dragonne (called something else in my world), the "incomplete" (wingless) Drakes, Linnorms and others are far more common nowadays than a great winged dragonfire-breathing wyrm. The major problem for dragonkind is that they are breeding "true" progeny less and less as the ages continue.
There is a council of dragons -predominantly metallic but a few very ancient and wise chromatics who have eschewed their wicked ways. Their purposes are their own, as their existence is not widely acknowledged except among wizarding circles. They are said to oversee the magical training and empowerment of a singular champion of Magic for the world of Orea, the Dragonmage. Their "hall" is rumored to exist at the farthest edges of the mountains at the top of the known world.
The dragons that were made attuned to the crystals and gemstones have been all but lost to Orea. Or so it is said/believed. The dragons of Emerald, Sapphire, Ruby, Onyx, Amethyst and Quartz are individual entities. They are generally agents of the god of knowledge and the mind, Sorilore the All-Knowing. These dragons take great pains to keep their existence -let alone location- a secret. Each of the gem dragons head or are patrons of orders of psychic individuals and various mental powers and prowess. For the most part the groups adhere to a communal policy of non-interference, and mutual secrecy, but disciples of the Ruby and, oftentimes, the Onyx tend to find themselves at odds with the others in sinister schemes for psychic power and asserting their supremacy over other mentalists -if not the entire world.
So, dragons exist. They're around. You probably wouldn't know if you encounter -or are near- one, unless they want you to know. The number of known dragons' lairs are...few and far between. Great wyrms laying atop vast piles of riches and magic are more legend, these days, than history. The tales of Varkaasik the Terrible (a great red dragon) in his treasured hall in the Drakkenmount range or the horrific Yrss Undallig, a dragon more ancient than the Godswar, said to be enslaved (or kept as pet or mount or partner, depending on the tale) by the unspeakable lich-lord, Kren Dalek, in his dread domain can be entertaining around the tavern fire. But, no serious-minded person, nor many fools, would take them seriously.
...Of course, if one /did/ find a true dragon's lair and hoard...