One Verb for all means different games of same genres have similar keys or controls helping the user to advance on learning curve faster. If games with the same genre have same keys, players won't waste their time in learning the controls and their reaction with game surroundings would be faster, which makes the game more engaging and subtle for them. So everything comes down to the player's skills. For example, most of the FPS game like Call Of Duty, Battlefield, and Counter Strike have similar controls for Reload, Primary Fire, Secondary Fire and movement keys.
Other thing I meant by one Verb for all is having game/user interactions mostly on one key so that user won't have to worry about learning different controls for different actions and focus more on gameplay. Moreover, it reduces the player's time spent on controls menu remembering the controls. It makes gameplay more engaging. Some of the games which implemented one input for various actions beautifully are Assasin's Creed and The Witcher 3. Assasin's Creed has implement free run, climbing and swimming on similar controls, and Witcher 3 have interaction dialogues, ride, inventory, cinematics start and end, react to the system on one action key, which made so relaxing and engaging for users.