Fixed the stick drift in my left Quest 2 controller. Turns out there's tiny little metal contacts underneath the analog stick that make contact with the circuit board. These metal contacts start out curved, but as you use your controller, they start to flatten out and don't make as good contact, causing stick drift. Fixing it was as easy as disassembling the controller and bending the contacts into a curve again, but the design is such that I'm only resetting the problem for another year or so.