"What most people making these stories don't seem to get is, multiverse stories are boring."
When poorly or lazily written? Yes they are but not inherently so. There are several good multiverse based stories, like anything else it depends on how you write it.
Obviously when you use it like Neatherrealm MK or Injustice does, ie as an excuse to casually kill off characters consequence free 'cause you can just replace them with an alternate universe version who just happens to be basically the exact same, that's hot garbage.
Now personally I prefer multiverse stories which feature multiple characters from different parts of a franchise interacting (ie Dissidia Final Fantasy, the climax of Digimon Young Hunters etc.) as opposed to the different timelines variant where it's different versions of the same characters but regardless, weather it's good or bad comes down to how its written and isn't inherent to multiverse stories.
Modern multiverse stories being almost universally terrible is the same as Superhero and Star Wars stories, the reason they're sucking right now is just because of the bad writing they're plagued with, nothing to do with the types of stories themselves.
