Yes, your hard drive will fail and all the data will be lost, it's just a matter of time.
Based on my experience, hard drives are the component that fails the most out of all the internal PC components (second would be the internal power supply) especially older style platter hard drives, imagine an old record player spinning the and playing the same record for 3 -5 years 24 hours per day that's essentially what the hard disk has to do.
You should assume that your disk will fail "at any moment" and strategize your backup, duplication or redundancy strategy based on that assumption.
However even with good strategies in place it can still be still painful and expensive when a drive fails. I have recently added hard drive monitoring software to my standard recommendation for mission critical systems and really any other PC that can't be replaced by a simple reimage, "the accounting lady's PC" is a good example of a unique complex system where a disk failure can be very painful and costly.
My recommended software for this purpose is HD sentinel (https://www.hdsentinel.com)
See the screen shot below for an example of the display you can opt to have this open at startup and or monitor and email is there is any issue. Note also for server's its able to "see through" the RAID array and monitor the disks directly*.
For HD sentinel professional:
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Treat this information as informative only and do not take actions or make decisions on the basis of the information contained here. All IT decisions and actions should be made after consultation with your chosen IT professional taking into account all the of the relevant factors.
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Digitalwelcomemat provides IT consultancy and services for business customers on the NSW Central Coast in Australia.