Can you give some example? I mostly also care about energy efficiency. How much energy would the alternatives consume?
Even the better low-end N100's usually idle at 5-6W, which is double the Pi 5.
SoC idle temperature depends on environment and cooling solution; the N100 would quickly thermal throttle if you don't have a comparatively large heatsink attached. The Pi 5 will actually give you full performance for a minute or two before throttling (assuming no heatsink).
Other Arm chips are much better, efficiency-wise, but the Pi 5 is still more efficient than any low-end x86 build, especially used.
I’m sure you have many more topics and a ton of other gear to explore to explore and many pi-related videos are fun entertainment (which is fine for it’s own sake) but it always practical.
That 4-SSD nas looks fragile as hell and I think it’s definitely worth exploring alternatives.
But it is not low-end for sure. I'm kind of wasting the computer on this use case. It's just what I had after Pi 1B turned out not being enough.