Jes got bak in the game when did stadium battles tak over ?

Stadiums have actually been a part of the original TCG for a very long time. While it's true that certain Stadiums favor specific decks and even make them viable, saying they've completely taken over isn't really accurate... you could easily say the exact same thing about Tools, Items or Supporters.

They are all just core components of the game, and Stadiums have already proved how much strategic depth they add in the original TCG... so TCG Pocket adopting them was only natural and expected.