Yeah, seems you're right. But! Seems there are a bunch of other hardware-related workarounds for getting CEC to maybe work, depending on the full setup you're using: https://wiki.archlinux.org/title/HDMI-CEC#Hardware_setup

For example:

> The PulseEight USB-CEC adapter works by passively extending all the pins of the HDMI connector on from the "PC side" connector to the "TV side" connector, save for the CEC pin, which is intercepted. The data going through that pin is instead exposed over a USB serial interface to let a PC control and monitor CEC traffic

Edit: Ah, but that adapter wouldn't work for powering on the PC I suppose, I don't think USB has something like WoL.