>>105643438
>Even old drives?
No, old drives were different.
>2012
This is modern technology.
>why is it a waste of time?
I said it could be. Not that it is.
You have backups of the data and are just hosting replaceable media on it, a quick zero fill should suffice and if no issues pop up scanning after zero filling may not be worth the extra time.
If you don't care about the extra time, it's worth doing a read test after the zero fill and checking SMART again to see how values (if any) changed as a result.