I just replaced a drive today that has been running 24/7 for the last 5.18 years. It hadn’t failed yet but was in a predictive failure state due to the amount of bad sectors it has accumulated. 3 other disks in the same giant raid array are showing some bad sectors but not enough to be over the ‘replace me now’ threshold.
Your post inspired me to pull my old PS3 Slim off the shelf and give it a shot. Fortunately it is one of the ones capable of custom firmware. I successfully jailbroke it and am now running custom firmware, next I just have to figure out how to do anything useful with it, lol.