When you're chasing minimum power consumption, tho, a Pi4 (in my case, a CM4) with a 200MHz base clock, a USB3 card, a SATA card with 6 SSDs attached, running 3 Alpine VMs and a couple Docker containers will idle at 12W and perform surprisingly well when asked to while drawing no more than 27W with every system running at full tilt. I didn't expect it to be as good as it is, and I can't find anything else that can touch it. But my use case is narrow and specific.