Same place as everyone else. They’re just a peculiar bunch of people who get more enjoyment out of supporting the players than being the heroes of the story. Not having one of those people means you are not equipped to play the game, just as much as if you didn’t have dice. You can try to put someone else in that slot, in the same way you can try to play Eberron as a setting using Werewolf: The Apocalypse rules, but your expectations will need to be low.
Where do you think DMs come from?
Same place as everyone else. They’re just a peculiar bunch of people who get more enjoyment out of supporting the players than being the heroes of the story. Not having one of those people means you are not equipped to play the game, just as much as if you didn’t have dice. You can try to put someone else in that slot, in the same way you can try to play Eberron as a setting using Werewolf: The Apocalypse rules, but your expectations will need to be low.