Why are USB-C docks with lots of fully functional ports so uncommon?

The main limitation is the hub silicon. USB hub controllers commonly support one, two, or four downstream ports. A product with more than four ports usually needs multiple chips connected in a chain, which increases cost, power use, latency, and compatibility problems. That is hard to justify for mainstream products when most customers still use USB-A or only need a few ports.

The issue generally is not licensing. It is cost, available controller chips, power delivery, bandwidth sharing, and the fact that USB-C is a connector with several optional capabilities. A dock can have five USB-C sockets while only four are actual downstream data ports, with the remaining socket reserved for host charging.

Daisy-chaining hub chips creates another restriction: USB has limits on how deeply hubs can be cascaded. A large hub may work normally with basic devices but fail when another device contains its own internal hub, such as certain serial adapters or card readers. This is one reason a smaller, carefully designed dock can be more reliable than a cheap hub with a huge port count.

Multi-port hubs do exist, but the ports are not always equivalent. Some USB-C connectors support data only, some provide charging, and others may support video or USB Power Delivery. A port labeled USB-C does not automatically offer every USB-C feature, so manufacturers often include fewer high-function ports and use USB-A for simpler peripherals.

Thunderbolt 4 or Thunderbolt 5 docks are worth considering if you need several fast USB-C connections, but they are expensive and still often include USB-A ports. The market is also slow to move because USB-A remains common, while many inexpensive USB-C products are really just charging distributors rather than full data hubs.