Really? You felt it necessary to denigrate my post based on what experience? How many times have you actually found slow USB transfers in practice?

In >30 years of using/building/repairing computers I've seen hundreds of hard drives slow down as they start to fail.
I've only ever seen two transfer rate problems that were not down to the drive. One was a damaged cable and the other was a new enclosure with a manufacturing defect - but that was slow out of the box and went straight back.