I'm ignorant on this topic, can you not just plug a USB dock with HDMI out in any android phone and get a display out? I do it all the time on the previous three pixel phones I've had, but I didn't know that this was limited to those?
Some USB-C devices only use the port for charging for example. Others might only support USB 2.0.
Getting a display out from something with USB-C socket needs the device to support something called DP Alt Mode.
Note that cables matter too - you can have a DP alt mode enabled monitor and phone, but if you have the wrong cable it won’t work. Welcome to the future.
To mitigate the confusion, all simple charging cables should be universally labeled as such and all high speed cables should also have some markings that indicate the maximum speed of the cable or something similar.
labeling hurts profits.