After Humans Disappeared, They Became Legendary Creatures

[Technology vs Magic, Slow Heat] The glorious civilization of mankind has disappeared into history for unknown reasons. The elves worked on the assembly line of the steam factory, driving screws for their king. The grasslands and forests of the original ecological park have become the territory of groups of orcs. The dilapidated floating city became the dragon's new home. Human beings have become what they call powerful and terrifying ancient creatures. They are more terrifying than demons and more powerful than gods. Elven archaeologists search underground for relics of humanity's past, waiting to revive that great era.