One of the most commonly encountered problems with USB-C hubs stems from the fact that many of them use power from your computer instead of utilizing a direct line to an outlet. Similarly, a USB-C hub is splitting its bandwidth from the laptop port it's plugged into, while a dock has its own dedicated bandwidth. These two limitations combined mean that not every piece of tech will run well on a USB-C hub. External hard drives, particularly SSDs, can struggle to get enough power and bandwidth to function properly, and the high-speed data needed for devices like HD webcams and external GPUs to function properly makes them a nonstarter with a hub. This is also why most USB-C hubs can only support one external monitor — there's simply not enough bandwidth for more.
Because they're designed to be more portable, USB-C hubs are also subject to the pitfalls of typical wear and tear. Compared to a stationary docking station, a hub is much more susceptible to things like debris buildup and internal damage from drops. Depending on how much you're traveling with it and how roughly it's treated, it might have a shorter lifespan than a dock. Despite their limitations, USB-C hubs can be a great option for users looking for more ports at their disposal, and their portability gives them a distinct edge over docking stations if you're not looking to plug in a huge amount of taxing peripherals.