Yup it has that mode, which to be fair existed in Tetris clones long before Tetris 99. I just meant that it had many more modes and I don't really thing that's the focus of Tetr.io? I could be wrong though I'm not a player.

the focus is primarily on 1v1 (tetra league); quickplay is a way to get introduced to the game maybe but it's not the main attraction