The fact that the GM has the last word doesn't mean that word is right. The world is full of bad Game Masters.
Aswell as bad players ...
And lots and lots other bad persons, and things.

Answer:
Everything that doesn't look and/or work the way it is supposed to be in the setting.
Yes ... this is perfectly logical and undersandable ...
Except that "is supposed to be" part.
Since your GM is the one who call how thigs "are supposed to be" ... and yet you dismiss that, since he "is not right" or "is a bad GM" ...
So ... since you said: "This is not "my liking", this is how the setting is built."
Im not quire sure where do you take how things "are supposed to be" ...
Bcs unless i understand it incorectly, you dont use your own opinions, nor opinions of your bad GM. O_o
See you always seem to not be in for a productive conversation. If we're talking about Faerun, which we are, there is countless content as to how the world works. Tons of lore inside books from every edition as well as novels, which you seems oblivious to their existence and try to equate your lack of knowledge in said setting by strawmanning and gaslighting people into your own obliviousness. Dragons can fly because they are magic energy incarnate, they fly due to their magical nature, not the strength of their wings. Devils are always Lawful Evil because Alignments in the Forgotten realms are primordial energies that have brought the universe together, and they are the representatives of said alignment, therefore if a Devil stops being Lawful Evil he stops being a Devil. ALMOST EVERYTHING in the Forgotten Realms makes sense because Mr. Ed Greenwood is a great world builder. If you go over to his Twitter you can see how ground to our own perception of reality the Realms actually are, set and self contained into their own laws of both magical and natural nature. To keep arguing that there's this huge chasm of understanding and whataboutism in regards to the "realism" and "immersion" of the Setting just shows how little knowledge you own on the subject and how little willingness you have into having honest conversations on the topic.
EDIT: Dragons are speculated to be able to manauver and fly due to their magical nature, yet in the Draconomicon 3.5E there's tons of info on their anatomy and biology explaining the whole thing.