Games like PoE, Diablo, Grim Dawn etc, all play better with the K+M due to the layout and general design of the game. A racing game is designed better for use with a steering and pedal setup, RTS and ARPG's play better with M+K, Platformers and action/hack n' slash with the gamepad.
Exactly, each game has well matching input methods. For instance I wouldn't like to play a fighter with the keyboard. Possible sure, but not as much fun as with a keypad.