It's been a long while since I experienced failure of the actual optical sensor. If it's not dirt or anything mechanically wrong with it, yung sensor na mismo ang problem. In which case, it's e-waste.

But kung skipping scroll wheel or double-clicking/intermittent buttons lang, I fix it myself. Dami sa online ng replacement rotary encoders and mouse button switches. Just get the correct one and choose the good kind... TTC or ALPS for the rotary encoder and Kailh for the switches, para tumagal.

Some Logitech mice use optical scroll wheel sensors (instead of encoders). They don't technically wear down, but my experience with them is that they sometimes get dirty (due to the grease from the wheel mechanism mixing with grime from your hands) and blocks some of the holes where the sensor beam goes through. This results in skipping and jumping when turning the wheel. I just wash it in joy to remove the dirt buildup.

Currently, I'm using a Logitech M585 and a couple of Rapoo M500 mice. All are wireless (w/ dongle) + multi-device BT capable.