Talking about building a server with a Zero 2 W is a bit of a stretch. I have some running as airplay and Spotify connect clients + some environmental sensors but much more would be pushing it...
No where in the thread was the "building a server" use case defined - the subject was always-on costs. That said, an RPi Zero works perfectly fine as a pihole (DHCP + DNS server), WireGuard node, a git mirror (running Forgejo), and many more use cases that are not CPU-bound.
Obviously, Raspberry Pis, SFF boxes, workstations and rack mounted servers all occupy different niches (with some overlap). Anyone confidently stating that one could fully replace anther with no context of the workloads is wrong.
The OP of the comment you answered was pretty much talking about how he uses his mini PC as a server and doing projects on it... and ofc a zero can do everything but at what speed? IOPS is disturbingly slow. I like the Zero for what it is but it's just not a good server fit.
I mean, I do projects on mine too. Without OP describing what the projects are; you're assuming they are CPU-bound.
Speaking of my projects - the RPi is perfectly capable of working as a web crawler (at a page rate that may surprise you) as well as a media download client & transcoder (again, simultaneously transcoding a number of streams that may surprise you).
Yes, the pi is perfectly fine for many projects, and in fact I have a couple of old pi's (even the original pi 1!) running tasks, such as listening sensors over bluetooth, pihole as DNS server etc.
The reason I prefer mini-pc's over pi is the x86 architecture and possibility to add more RAM. For maximum flexibility, I mostly run my self-hosted services inside virtual machines that I manage with Proxmox, and pi isn't ideal for that. Admittedly I found even the mini-pc's too limited due to lack of space/pcie slots for a GPU, and ended up with a custom desktop build. That allows me to experiment with stuff like self-hosted AI, and game remotely. Support for ECC RAM and more SSD's was a big plus too.
So, indeed it all depends on what and how much you want to do with the machines.
It's fine that it's enough for you and I applaud you. I was also not only talking about CPU but also IOPs some of us have more demand on what we call a server. I don't understand how you can be so defensive about a piece of hardware it's actually rather concerning and my zero w 2 does have problems with FullHD streams with high bitrates. It doesn't even have the io bandwidth to push more than one stream.
Add an SD card to that cost as well as an ethernet adapter, maybe wifi too? I'm not trying to bash on the Pi as option in all cases, just trying to note that in some cases, particularly hosting local services, it's likely not the simplest choice. Uses where I can see needing a Pi over a miniPC? Maybe 4k video playback, I'm not sure how well these x86 systems from 2011 can do that while some Pi's IIRC have onboard hardware for h265 decoding.
The RPi zero 2 is nowhere near powerful enough to be used for multiple purposes as any of the above machines.
It could probably run a single-task relatively well, like PiHole or something, but otherwise it's in a completely different performance category. Like an order of magnitude.
So 6W idle for J5005 would put it on the same level of efficiency.
You're right, the RPi zero 2's CPU is slower - but that doesn't matter for non-interactive tasks. I don't care that my cloud backup export cron job runs 5 minutes (or hours) longer on the Pi than on a Nuc; I only care it happens daily. For the CPU-/GPU-heavy workloads, the RPi Zero W is works as an orchestrator for the > 10W computer: powering it on and off as needed.
