A year or so back I debated whether to keep my home server/PVR running or leave the Studio running instead. When I measured, my M1 Max Studio idled at 15W which worked out at a bit over £40/yr if it was left 24/7.
The Celeron-based HP home server used 23W with just the system SSD*) and an older PC built around a mobile-class i7 (27W with just the system SSD). Both of those were always designed as low-power systems to be left on continually. So, yes, the Studio is significantly lighter on power but it ain't gonna pay for itself any time soon!
* The usual complement of 3x4TB hard drives added 12W - but I'd need to add something like that to whatever system I used as a home server.
The practical upshot was to say "neither" and whittle the files I actually needed always online down to fit on a single SSD hooked to a Raspberry Pi that pulls under 4W and still does the PVR stuff.