The controller runs off a membrane button interface that sits between the front faceplate and the mid frame housing that mounts the PCB. This is a decently cheap part for replacement if you're willing to open the controller. Replacing the rubber parts behind the push buttons should be completed at the same time. R1/L1 and R2/L2 use this same membrane with a spring mechanism to give the feel of a trigger. Search Terms: Dual Shock 4 replacement film. Dual Shock 4 conductive film. Estimated price 10USD. Stick drift. Replacement of broken analog sticks is difficult, there are numerous through hole solder joints that must all be molten at the same time to release the button. It is doable with a basic soldering iron, just takes time and lot of patience while you slowly wiggle out one side and then the other. Expect to pay 1-3USD per analog stick. Joystick caps are 10 for 10USD on almost any online marketplace like eBay and Amazon. Numerous videos and websites and step you through opening the controller without damaging the small ribbon cables that connect from the back cover to the PCB on the mid-frame.

I'm curious, original controller or the version with the light coming through the touch pad? I got my playstation almost at launch and bought a secondary controller shortly after (so both controllers are the first version). I don't know which one broke last year (R2 button only) as they are both the same color but the other one is still going strong. Only the rubber in the sticks has gone. As for usage, it's not daily but it's several hours per week. I am thus considering if it's worth it to buy a sony controller or third party as i know very little of quality nowadays.