A big reason joystick drift is a thing is that current controller designs allow dirt, grime, and dust to enter the small gap that connects the joystick and controller. The DualSense joysticks have a small gap to allow for smooth movement and this gap is large enough for smaller dust particles to enter the entire joystick. If dust, crumbs, or something similar gets into the sensor component called the potentiometer, it could cause the controller to register stick movement when none is taking place.
Unfortunately, that means there’s really no guaranteed way to avoid the problem unless you never use your controller’s thumbsticks. Although most people think that debris is the most common cause of drift, that is not necessarily the case. I fix it studied the phenomenon and found that the vast majority of drift issues stem from mechanical issues such as wear, which occurs naturally over time when the controller is in use. The team also detailed a potential permanent solution to the problem, giving players hope for a less frustrating future.
This is similar to an issue that plagued Apple’s butterfly keyboard design. The gap, while small, was large enough that dust particles could get stuck between the keys, causing some to stick or register a double press even if the user only pressed one. times on the keys. The two issues are more or less identical – although, in the case of the DualSense controller, instead of involving stuck keys or double pressing, you have to deal with ghost joystick movements.