Tetris as a whole is one of the greatest video games out there, but not every tetris game is created equally. Tetris DS felt like a turning point for the franchise forr me, where we left the Classic Tetris era started by the original gameboy release, and entered into what can now be considered the Modern Tetris Era.
Basically what Im saying is is that Puyo Puyo Tetris' Tetris mode wouldnt be as fun as it is without the QoL improvements brought to us by Tetris DS