Mans greatest fear is the unknown and certainly top of that is death. Well what happens when we die.  To the point massive parts of our history and even social construct is based on what we think happends when we die. The End Time or the complete lost of human race is just that fear dialled up to 11 out of 10.

Without going to much into faith or myths that cover religion throughtout history most have some form of Armageddon as a key to element. Because if the fear of death and what happens after keeps people in line then the idea of a total loss of humanity keeps the general masses inline.

Man has always been obessed with it. They even have a word for the study of it Eschatology (Yes I know be careful how you type this into google).

Not sure I have heard Ragnarok as just being “New Years” The word translated means “twilight of the gods” It is the end of the gods which brings on the birth of the man. So it is Armageddon but just for the gods I guess.

I guess given this rich background and honestly even if you dont like religion boy the “end times” they come up with is a cracking hoot in most cases. Of course if you assume none of it is based on fact which if it was is pretty scary.

I say that but like Ragnarok, most are based on a sense of rebirth so amny not quite as a scary.

I guess it should not be a shock it is the focus of so much material in RPG, tabletop it is just a mirror of our own life and struggle through history to this point.

Fantasy Flight used to do a D&D campaign setting called Dawnforge that is set during that worlds golden age. Very much the opposite of the usual grim dark settings of most other worlds.

https://www.fantasyflightgames.com/en/products/dawnforge/

That is not totally true, I mean in Skyrim dragons come back in full force as a general nuisance and they still have a civilization of sorts in that and honestly doubt it was hard to write. Yeah a lot video games and Manga setting actually do have worlds where races like the Beastmen or Elves are at the height of their power (generally as rank bastards that view other races as livestock and devalue sapient life) and have fantasy critters out the wazoo which are often treated as just regular animals in the setting.

The final “this or that” idea being popular probably has to do to with the absurd British philosophical concept that “Magic died out like the dodo for X reason” that was popular in the late 19th century among scholars,  occultist, Atheists,  fairy story collectors  as opposed to ideas about Ragnarok (misunderstood calendar cycle or no). Tolkien was likely deeply influenced by this way of thinking as there was a lot of that 19th century media was readily available to him, and if you influenced Tolkien you influenced modern fantasy.

“The death of magic”  often comes up in fantasy works by skeptics and the others as the brain dead “we can slay God(s) by not believing in them” except with “magic” replacing “God”. The fact is that if creator God(s) exist they would likely continue exist weather you believed in them or not and in the case polytheism creation would quite possibly egg your house or mock you publicly in ways only gods could do if you did stop believing in them, the same would also be true if magic (fireballs and fairies magic that is) where real.

Some however, like Tolkien, posit things like immigration due to boredom (elves leaving middle earth by boat while sad for Middle Earth is not really the the end of elves) and simple extinction due relatively realistic reasons (Ents can’t find Entwives? the citizens of China are in the same boat).