My G500 started double clicking within a month of purchasing it. I just bound left click to a side button and never looked back. I've been using that broken mouse for over a decade now because they're just that good.
Logitech was so close to creating the perfect mouse. Why they haven't fixed their terrible internals is beyond me (planned obsolescence aside).
I still feel that way about the old MX510/518/400 line. When the G series first came out, Target had a whole shelf of MX518 on 90% off clearance and I bought them all. Gave a bunch away as gifts, but they lasted me almost until Logitech made the re-release of the MX518 with newer internals. I bought a few of them and am still on the first one after a few years. I bought a 502 on clearance to see if they were any better than the MX518. Nope, so it's now living in the backup hardware box.
I went through so many feet on my old MX510 and MX518 that I bought a huge roll of 1/2" wide industrial teflon tape to put over the feet. The newer models have much bigger and thicker feet so that's not needed anymore, but man those old ones wore away quick.
I'm still on the 500, and I have a couple I got way back. I'm hopeful that when they eventually die, Logitech has available something decent. I don't have much hope though.