USB extenders do work, according to Engadget, and they let users connect devices across longer distances than a standard cable would allow. However, the article stresses that not all extenders are equal: different models have different capabilities when it comes to performing that basic function.
The key variable is the type of extender. Some simply extend the physical cable length, while others use active electronics or network-based conversion to bridge much larger gaps. That distinction affects both data transfer speeds and power delivery, so a cheap passive extension may work for a keyboard but not for a high-bandwidth drive or a bus-powered device.
Engadget also notes that safety is a consideration. The article does not claim all extenders are unsafe, but it points out that quality and design matter. Users should match the extender to their specific device and USB standard rather than assuming one size fits all.