It's important to bear in mind that not all USB Type-C connectors are equal, although they look the same on the outside. There are nine different implementations, or as many as can theoretically be encountered, but not all of them are used. This is indicated by The Universal Serial Bus 3.1 specifications, which represent a 24-pin USB-C connector as well as a number of innovations that greatly expand the possibilities of USB use. Importantly, the new specifications maintain full backward compatibility with previous versions of the standard.
The main idea - the idea to create a connector that can do basically everything - has been known for a long time. It is designed to connect classic peripherals and storage devices, for which data lines with throughput of up to 40 Gbps are used (however this is only provided by Thunderbolt). It can also connect two monitors or other display devices, even with 4K resolution at 60 Hz, and can supply up to 100 W of power to the connected device. It uses Thunderbolt, DisplayPort, USB and PCI Express protocols. However, implementing all of this is nowadays expensive and often unnecessary, so it's no surprise that different versions of USB-C keep popping up.
As a result, the individual implementations can vary widely. On one side, there's USB C with USB 2.0 support only (480 Mbps), and on the other side, there's USB C with Thunderbolt support (40 Gbps) and power options (PD Enabled), with seven other possible versions in between, differing only in PD and support for different interfaces. We learn about the capabilities of a given port through the nearby pictograms, as shown in the image above.
Because of this, the mere information about the presence of a USB-C connector means nothing at all. It could easily be a simple and slow USB 2.0 in the end, or on the contrary, a modern interface connected to an Intel Alpine Ridge controller, which offers everything USBC can use. Thereby supporting Thunderbolt 3 with 40 Gbps.
Eventually, the situation should calm down, as all USB C is supposed to progressively offer 10 Gb/s and PD throughput, but currently it does not look like USB C will bring simplification and unification of the entire interface, rather the opposite. On the other hand, it is the diversification and the ability to produce cheaper hardware with USB C that will allow the interface to scale faster.