None of that is reason enough to abandon the concept just because it's superheroes. Should no one make a superhero themed game ever again because a Marvel game is being made? No, that would be stupid
Those are good reasons to abandon a superhero MOBA with flying concept because:
• Your studio cannot compete with other games in the quality side if we look at Drawn To Death.
• Your studio is making a game which is going to compete with other MOBA games for the spot in the graveyard
• You have no IP to work with, which makes it much harder to market, and creates a ton of concept/character building. When people remember Lawbreakers, everyone always contrasts the characters/world of that game with successful ones like Overwatch. Turns out that it is actually hard and expensive to build appealing characters.
And when I say a graveyard, I mean the ever growing pit of unsuccessful MOBA games like Infinite Crisis, Paragon, Breakaway or Gigantic.
Both Marvel and DC had unsuccessful super-hero games. Even with marketing, budget and IP there is no guarantee for success when it comes to online PC games.
Studios should evaluate their own capabilities before embarking on competing with both MOBAs and successful superhero IPs at the same time.