In the bad old days before SMART, you HDD failed with uncorrectable errors and data was lost. No warning, no alerts, just poof it fails without warning.
Now SMART tells you it relocating sectors before the drive fails with uncorrectable errors. This gives you a warning and time to rescue your data.
SMART statistics come from the hard drive, re-installing the OS doesn't help. Drive is starting the fail. Eventually it will fail with an uncorrectable error.
Using the that drive is like driving a car with an oil light turned on. Eventually it will stop working and leave you stranded; you can get your car serviced to take care of the warning for far less than the cost of a new car. You can do the same by sending in your drive to a data recovery service and they can "clean" the drive for several hundred dollars. It's not cost effective to fix the drive, just buy a new one.
Bear in mind that you're probably getting relocated sectors because the inside of the drive has contaminants. These will spread until there's no more sectors to relocate data to, at which point you will get an unrecoverable error. Continue using the drive at you own risk.