There’s a rule I was always told in A+. Either a hard drive is going to last you less than a year or it’s gonna last you five. Usually any problems with a hard drive you’ll see right away. However after the third year is when I’d start checking the drive. There are tools out there that can let you know when a drive is in the caution level and that’s when you should think about replacement. I’ve had hard drives like one I have to replace soon last me eight years with constant use as a Plex drive.