It'll tank as a casual game, it'll tank as a spectator's game and will in turn tank as a competitive game. A game can be as technical as it wants, but the sad truth nowadays is if the stream wont watch it, the tournaments wont host it.
You worry too much, you negative nancy. Or maybe you want it to fail for whatever reason.
People will play it if they want to play it. And if it plays well, it'll succeed. You lean too much on graphics. SFV isn't really the most beautiful game out there either. Almost look like claymation, very stiff models - just look at how Laura's arm keep glitching through her plastic-like hair. Graphics-wise, that's unacceptable in this day and age. Yet people are super excited for that game and people, including yourself, really like Laura's inclusion into the game.
KoF does indeed look low-poly. And like I said, hopefully the graphics will become better. There needs to be a balance between gameplay and graphics for a game to become successful today. But as proven in the example I made above with SFV, people can be forgiving about how a game looks if it just plays well.
Another example is Dead or Alive 5. It looks beautiful, but the gameplay is subpar, which is one of the main reasons it isn't all that successful. Gameplay is indeed the most important thing in a fighting game. A pretty coat of paint won't win over the hardcore base.