Recently completed a new build with Asus Strix z390, i9900k cpu and Seasonic titanium psu so thought how much power it consumes, so used a watt meter at the socket to measure the power draw and found something interesting,
Shutting down the Windows (but not disconnecting power) draws 3w occasionally touching 4w (USB power disabled, LEDs disable, but not EuR power saving ebabled as that makes computer do double boot).
Sleep mode - 4w
with my old build this used to be 3w off and around 10w sleep so looks like improvements to power savings in the CPU and memory have made massive gains. With the benefit of not having to close anything and instant start, I am going to use Sleep button from now.