GPUs last really good when they are used for mining. Mining BIOSes often undervolt/underclock a GPU that it runs actually more stable and doesn't have nasty peaks in power consumption.
All of the GPUs that I have received for repairing have broken down during gaming or by physical damage.
where to get those mining BIOSes from

Also how to go about undervolting the GPU if needed to prelong their life ?..
thanks,