I have a rack setup and most of the time it consumes around 200 watts during the daytime and 100 watts at night, but can spike upto 600 watts if I put a heavy CPU+GPU load on it.
I also put my desktop into suspend at night, something which I think a lot more people with desktops could do. Don't run 24/7 services (e.g. Home Assistant) on your massive desktop with an i7/i9 and a GPU. Run that stuff on a NUC or Pi4 or anything that has low power consumption. Then turn your desktop on only when you're actually using it.