The N100 has a TDP of 6W. I haven't measured power draw of the whole system yet though, I imagine that the mainboard will pull another couple watts at least.
It shines especially in scenarios where the Pi is just a tad too slow. E.g. you can't live transcode 4k videos on a Pi, while the N100 has latest UHD graphics and therefore ships with a decent HW-accelerated H265 en/decoder.
Sure there are, there are lots of NAS appliances boxes from the likes of Synology/QNAP/Aliexpress Special that can run double duty as servers built on similar low power CPUs. Some of them even have decent networking options.
The problem is that a lot of the commercial products are woefully underspecc'ed for the price and you outgrow them quickly. Spinning disks also eat a lot of power, relatively speaking, so they kind of eat into the "low power" usecase.
You should actually look at what's available. You can get a QNAP box with an ARM CPU with lots of drive slots, dual 2.5 gig Ethernet and dual 10 gig SFP+ for like $700, among many more examples. Sure saturating those is gonna eat a ton of cycles and run like shit but... yeah of course it is it's a cheap low power CPU. They suck for the sorts of stuff I wanna do, but this is inherently a market segment that involves compromise and that is probably perfect for some people.
I agree I'd much rather roll my own system (and that's what I did) and I would personally never buy one of those, but it's simply not right to say there are no options available if you want a low power server off the shelf. Some of them are even decent if you wanna pay for it.
It does if you want more than a storage appliance. I want the option of setting up any linux server software on it if i feel the need. Just a general purpose low power computer.