Google has nailed the Pressed State for buttons in their Google Material Design System, Why? Well, It's subtle for one but more importantly, it gives the right Affordance to what has just happened. After you click you know the click has worked, and in this interaction also adds the added benefit of letting the user know where exactly the click has taken place by creating a ripple effect emanating away from the place where you have clicked. For more check out https://johnferreira.design/learn

button, pressed, interaction, microinteraction