Most are similar to well-behaved appliances - so low it's difficult to measure. Even more so if they are not wifi.

I have one in my desk that's then plugged to a power strip so it can cut power to multiple devices at once. It can even measure power consumption – sitting at around 80W as I type this, with a laptop, 34" monitor, Echo, wireless charger, USB switcher, USB hub, a desktop computer currently 'off', standing desk, laptop dock and the list goes on.

It's OK, there are smart plugs you can use, to cut the power to them.