The truth is at todays prices for rotating rust (ie. HDs) they aren't worth the labor to repair. Its cheaper to just toss them. Installing a new drive in an older enclosure is also questionable, because you can buy a new drive in a new enclosure potentially with a significantly faster I/O bus (USB 2 vs USB 3.0 vs USB 3.1 vs USB 3.2) for not that much more than you would pay for the drive alone.
