Something with an i5-6500T ($100-$120 in an 8/256 config) is insane bang-for-the-buck relative to a Pi. Especially with the tendency of Pis to multiply.
My main hesitation with buying the used USFF has been the Intel Graphics generations - I don't know enough about it, but I do use my mini PC for Plex, and have a hard time comparing the integrated graphics, which is critical. These N4000 destroy the i5-3450 I have in my NAS. It was cheaper to buy an N4000 and put Plex on it over network access, than it was to completely upgrade my NAS to a new generation of hardware, and the newer QuickSync version can actually encode with Plex.
https://forums.serverbuilds.net/t/guide-hardware-transcoding...
My original "Pi for PiHole" replacement 5-6 years ago was a used AMD GX-415GA NUC-alike that I spent less than $40 on and half was for an SSD. I keep it around still because it cold boots incredibly fast and if there's anything you want to boot really fast, it's the thing running your DNS.