I use an all in one. Linux host for hypervisor. Windows 11 with virtual tpm and gpu pass through for gaming, and a FreeBSD guest set up with 1 virtual hard disk, one ssd for boot mirror, and 3 2tb platter drives for file serving. At idle it takes about 80 watts (including the router hooked to the ups) per hour. Definitely more than a raspberry pi, but it really only burns 1-2 kWh a day which comes out to .30 a day for us (roughly).
The amount of time it would need to be running before it was cheaper to use a raspberry pi including everything it needs was almost 6 years of 24/7 uptime for our electric rate so to me it makes 0 sense to run this differently and separate. There are also more efficient at idle chips nowadays.
System specs: Ryzen 7 2800 8-core processor 128GB ram Gt 1030 video card for host 3060ti for windows vm 2 1 tb nvme drives 2 500GB ssd (one for boot, one for zfs cache FreeBSD) 3 2tb platter drives