For some reason, Canon 5D Mark IV does not work properly when it is connected via USB-C cable to a Mac with the Apple M1 chip. Canon EOS Utility and Adobe Lightroom both don’t recognize the camera.
However, we found a simple temporary solution. If you use a micro 2.0 USB cable instead of a USB 3.0 cable then it works. Basically, it goes to the same USB 3.0 port of the 5D Mark IV body but only half of this port will be used physically. Yes, you heard it right. You can use a micro USB 2.0 cable with a USB 3.0 port. Wikipedia has a paragraph about backward compatibility.
The speed will be limited to 480mbit/sec. Not perfect, but acceptable. Unfortunately, Live view in Lightroom would be hard to use due to lower bandwidth, but it is at least something when you need to tether your 5D Mark IV.
Below we attached two screenshots of when the camera connected with USB 3.0 cable and with micro USB 2.0 cable. As you can see the camera is recognized on a hardware level in both cases, but currently working only when connected with a micro USB cable.
Don’t forget you would probably also need a USB-C to USB adapter.
Update (June 16, 2021):
Looks like the issue was partially fixed with 1.3.3 firmware update. Live View is still hard to use, but you don’t need an extra cable anymore.