Just checked my Sony Android TV from 2019 and found it is drawing 16W while turned off. Turning off the Chromecast built-in service, the remote start service, and enabling Eco mode did not seem to make a difference. I already disliked this TV and was unlikely to buy another from Sony (for example occasionally it will “crash” while in standby mode and stop responding to any input, requiring me to unplug it and plug it…
If that still fails, try disabling wifi and disconnect the ethernet