It appears to work fine (it contains my home partition for my main machine I daily drive) and I haven’t noticed signs of failure. Not noticeably slow either. I used to boot Windows off of it once upon a time which was incredibly slow to start up, but I haven’t noticed slowness since using it for my home partition for my personal files.
Articles online seem to suggest the life expectancy for an HDD is 5–7 years. Should I be worried? How do I know when to get a new drive?
First rule, always have backups. Especially with an older drive, make sure anything you might need is duplicated somewhere else. Ideally off-site to prevent loss in case of things like burglary or a fire. Even something as simple as Google Drive or OneDrive.
Personally, I’d take a look at replacing it with an SSD if you can afford to, not only because of the age, but better performance. You may not notice slowness, but making the jump from a HDD to an SSD is still at least a little noticeable even on secondary drives from my experience.