There may be several causes for stick drift. The most common ones are potentiometer degradation and dust/debris buildup. The latter one is self explanatory.

Most controllers use potentiometers to detect the position of the stick. Potentiometers are mechanical components that measure changes in electrical resistance based on the stick’s movement. Over time, the constant friction from moving the stick wears down these components. This can lead to inaccurate readings, causing the controller to register movement even when the stick is idle.

Hall Effect joysticks use magnets and sensors to detect stick movement without physical contact, unlike traditional potentiometers that wear down over time. With no friction, Hall Effect sensors avoid the wear, dust interference, and mechanical degradation that cause drift in traditional sticks. They offer precise, reliable performance that remains consistent over the controller's lifespan, making stick drift virtually impossible.

Hall Effect sensors have been around for decades and were even used in some earlier console controllers. Despite their durability and resistance to stick drift, manufacturers may avoid using them due to higher production costs. We speculate that planned obsolescence play a role, as controller sticks with Hall Effect sensors would last longer than the companies support of the console, drastically reducing replacement sales.