I suggest you read wikipedia.org about USB-C and DisplayPort.
The signal at the USB-C connector of the CAC-1332 is DisplayPort. It is using the DisplayPort Alt Mode of USB-C. DisplayPort Alt Mode can include USB 2.0. USB 2.0 is used by USB-C displays like the LG UltraFine 4K to do audio, USB ports, and brightness control (all through USB devices). The LG UltraFine 4K requires four 4 of DisplayPort 1.2 to achieve 4K60. Some displays can do audio from the DisplayPort signal. And they can do brightness control using DDC/CI from the DisplayPort signal. I think the LG UltraFine 4K supports audio only from USB but can use DDC/CI to do brightness control (with third party app).
For USB-C DisplayPort Alt Mode, the number of lanes used for DisplayPort can be reduced from 4 lanes to 2 lanes so that the other 2 lanes can be used for sending and receiving USB 3.x. USB 2.0 uses different lines than DisplayPort and USB 3.x.
USB-C DisplayPort Alt Mode is used by USB-C docks and displays. Some docks allow 2 lanes of DisplayPort with USB 3.x, while some use 4 lanes of DisplayPort with USB 2.0. Some displays have an option or automatically switch between USB 2.0 or USB 3.x for the USB-C input (for example, if the display is using a different input, then it can use USB 3.x from USB-C).
The Apple USB-C Digital AV Multiport Adapter uses two lanes of DisplayPort 1.4 (and DSC). This allows the USB port to do USB 3.x.