Ah, perhaps I'm out of date then; when I say thin client I'm still thinking of the old Wyse box in my junk box with a Celeron, but that thing is ancient so maybe technology has advanced enough to blur the lines?
This does not match my experience unless you buy them day-and-date of release from a manufacturer who's slow to upstream system definitions. In my house I've got Rock64s, Orange Pi 3 LTSes, and just got an Orange Pi 5 (which stretches the definition of "SBC" in a lot of ways), along with a couple RPi3's and RPi4's. All have excellent Armbian support and, once you have Armbian installed, it's a bog-standard system.
They're also smaller, use less power, and tend to be less noisy. You trade off PCIe for most of them, granted, but more and more stuff is just "and I need a USB host over here" and for that they're excellent.
I wouldn’t go all the way down to “thin-client” like the Wyse stuff. NUCs and SFF/micro PCs are the next step up and usually have i3/i5/i7 CPUs… but depending on your needs, a thin-client isn’t out of the question.
