I've never had a Razer mouse completely fail, and I've owned quite a few.
1999 - Boomslang 2000
2010 - Mamba
2012 - DeathAdder 3500
2012 - BlackWidow Ultimate Stealth Edition (Keyboard)
2014 - DeathAdder Chroma
2018 - DeathAdder Elite
2019 - Mamba Elite
2019 - Huntsman (Keyboard)
Most are still in use actually by someone if not me. I still use a 2010 Mamba wireless at work. I did have to order replacement batteries for that one. The DeathAdder 3500 had an issue with the left button after awhile. Single-clicks were actually outputting double-clicks which was really annoying, but a firmware upgrade fixed that.
Now the BlackWidow keyboard I owned was terrible. It wouldn't work without drivers period under Windows 7, and function keys would get 'hung' and not work until it was power cycled, and other issues.
I finally got brave enough to try another Razer keyboard after the BlackWidow. I picked up the Huntsman, and it's been problem free so far. I found the "opto-mechnical" keys to actually be a nice upgrade from my HyperX FPS with Cherry MX Blues rather than just marketing hype.
I pwnz j00!