>the monitor draws 30W even in standby
That's absurd. There are regulations on standby power.
https://dl.dell.com/manuals/all-products/esuprt_electronics_...
>Power Consumption
>0.2 W (Off Mode)
>0.3 W (Standby Mode)
Doesn't seem to be an isolated case:
https://www.dell.com/community/en/conversations/monitors/up3...
>UP3216Q, drawing 23 watts in Standby? (2019).
I guess a takeaway from OP is to measure your actual standby power draw.