The Intel-developed Thunderbolt standard for connecting ... using a USB-C cable that's of a decent enough quality). However, while USB-C devices (like the HTC 10) plugged into a Thunderbolt 3 port ...
Although the dock seemingly only has a single HDMI output, you can use one of the downstream Thunderbolt 4 ports to connect another monitor either directly through USB-C, or via an adapter.
It also gives you the flexibility to plug in your laptop directly to the monitor, and can serve as an upstream port to connect other ... connected to the monitor via USB-C. The best part, however ...