If you are already running ethernet just use that for HDMI over ethernet. The various different USB-C cable standards are a whole can of worms I would just avoid.

HDMI Alt Mode allows HDMI video to pass along a USB-C cable dongle-free.

USB-C, which has become something of a "do-everything" connector standard, has added an alternate mode that eliminates the need for an adapter when connecting to HDMI displays.

The Cable Matters USB-C to HDMI Cable is $29.99 for Pixel phones. On the Google Store, it joins the HDMI Extension Cable and Multiport Adapter from the same brand.

The new Anker Nano USB-C to HDMI cable adapter supports 4K 60Hz video output from various devices and includes a separate USB-C port that enables fast charging up to 140W.

The 2-meter USB-C Charge Cable ($29) has USB-C plugs on both ends and connects to the MacBook for charging. Apple notes that it supports USB 2 for syncing and data transfer between devices.

Regardless, if the Google TV Streamer ends up having more than HDMI with 1-2 USB-C ports and Ethernet, Google is taking full advantage of the non-dongle form factor.