And dragons have faded into oblivion; even the description states how difficult it is to create them. In the worst case, you can create a spell to summon a Ghost Dragon from Dark magic (Incorporeal, absorbs 50% of damage. Applies a random curse on hit).
And in general, there are already many dragons. Although you are right, something has to be sacrificed, right? In principle, many options can be devised with dragons, for example, placing them among the neutral creatures.