LTSC
"Which is not meant for standard desktops, and on which Office is not supported, and the latest Office version wont even run on."
LTSC is fine for desktops. You'll be just missing the fancy metro apps, Edge and store. Perhaps it's actually even better than the vanilla versions then?
Office 365 won't run, but Office 2019 (PKC, volume) will run just fine. Lack of 365 could be problematic for many orgs, I'd agree.