The issue isn’t the Type A adapter itself consuming power even when nothing is connected, more it is an issue with how the CPU’s Type C controllers behave with the empty dongle/adapter.
The lowest TCSS power state is TCCOLD, which requires no device attached. A BIG part of how TCSS sees whether a device is attached or not is the Power Delivery communication over the CC pins. The PD chip on the board sees something connected to CC and it sends a message to the EC (I think) which then communicates with the CPU/PCH to inform TCSS that there is something connected and it needs to wake up. With a Type-C to Type-A empty adapter that PD communication still takes place so TCSS thinks that there IS, or at least COULD be a connection. In order to still work as the user expects (plug something into the empty dongle and it shows up) enough of TCSS needs to be awake to respond. The Phy needs to be powered, FIA needs to be powered, XHCI needs some power. I think that need for connection sensing on the USB3 pins prevents TCSS from being in TCCOLD and during sleep it is probably in TC7 which will consume more power.
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