USB hubs are fine for keyboards, mice and other things where a random disconnect is annoying rather than expensive. They are a terrible place to put important storage. If you are copying files, running backups or chaining external drives, the safest hub is no hub at all.
A hub is another failure point
A USB hub adds another controller, another cable, another power path and another set of ports between the drive and the computer. That might be fine for a keyboard. It is much less fine when the device behind it is the place your files are being written.
The annoyance is not only that a hub can fail. It is that it can fail in a way that looks like a flaky drive, a bad cable, a weird operating system issue or a mystery storage problem. You can lose a lot of time debugging the wrong thing.
The expensive ones are not always as different as they look
Branding, aluminium cases and a higher price do not automatically mean the internals are dramatically better. Teardowns often show commodity controller chips, repeated reference designs and protection circuitry that is missing, minimal or only good enough for ordinary desk use.
That does not mean every hub is identical. It means the outside of the hub is a poor guide to how much trust you should put in it. Too many hubs are small boxes of cost-optimised electronics pretending to be infrastructure.
Storage is the worst thing to put behind a hub
Storage cares about stable power, stable signalling and completed writes. A mouse reconnects and you swear at it for five seconds. A drive disconnects at the wrong moment and you can end up with damaged files, a damaged file system or a backup you thought existed but should no longer trust.
If the data matters, do not put a USB hub between the drive and the computer.
Shared power and shared bandwidth are not harmless details
Bus-powered hubs cannot create extra power out of nowhere. Powered hubs can still be overloaded, badly designed or awkward with devices that draw power unevenly. Either way, multiple devices are now depending on the hub to distribute power cleanly.
Bandwidth is shared too. A hub takes one upstream connection and splits it across downstream devices. That does not matter much for low-risk peripherals, but it matters more when multiple drives are transferring large files or a backup is trying to run while other devices are competing on the same path.
The corruption risk is the whole point
I have had multiple hubs fail. That is annoying on its own, but the real lesson is what happens when the failure sits in the middle of storage. A bad hub can turn a convenience problem into a data problem, and data problems are rarely worth the desk tidy-up.
People often talk about hubs as if the risk is only speed. Speed is not the scary part. The scary part is the unexpected disconnect during a write, the flaky power state, the half-finished copy and the slow realisation that the cheap little adapter was part of the storage chain.
The practical rule
Do not chain storage through hubs. Plug drives directly into the computer. If you must use a hub, use it for low-risk accessories, not backups, working drives or anything you would hate to recover.
This is not about being precious. It is about removing a fragile, replaceable middleman from the one path where failure can cost you files.
Research notes
Useful references: Western Digital on USB hubs not being recommended for external drives, Microsoft on safely removing external drives, WD on unsafe removal and data corruption, Apple on connecting devices directly when a hub has power issues, Microchip on bus-powered and self-powered hubs, Acroname's USB hub teardown, and ChargerLAB's branded USB-C hub teardown.