Game Controllers are always evolving. Going from a Joystick and a Single button of the days of the Atari 2600, to complex devices with a wide array of buttons, analog sticks, triggers, motion sensors, touch inputs, feedback motors, and video/screenshot sharing features.
But what comes next? What kind of technology or feature do you think, should be explored by controllers in the future, allowing for new kinds of input and immersion? Prior to the Switch, Nintendo patented a controller that swapped the L and R buttons with Clickable, analog scroll wheels.
I actually think this would be a simple and welcome addition to controllers, especially when using things like a Sniper Rifle in shooters. Being able to move the wheel to zoom in on a target, combined with precise gyro aim would be killer.
Another radical idea for a new controller feature (and I don't know if the tech for this is available yet) but what if a controller can change it's weight? Like the device physically feeling lighter, or heavier depending on in game actions, as well as shift that weight to different locations on the controller.
For example, say you're carrying something in a game, like heavy boulder. The Controller can adjust its physical weight to make it heavier, creating the sensation that you're carrying a massive, heavy object. Or, you're in a racing game, and when you steer a car, the controller can shift its weight in different areas, creating a sense of resistance and friction like a real steering wheel. This combined with current HD haptics, would be a goldmine for Immersion I feel.