They do, with Server 2019 for corporate servers. But your point is that no one is running Server 201x as their desktop OS, unlike the NT 4 .1 days, which then was rebranded into windows 2000, or NT 5
There's also the LTSC (Long-Term Servicing Channel) build of Windows 10[1], which doesn't have any of the consumer bits and bobs, and other than security fixes isn't designed to have any feature updates post deployment.
LTSC is fantastic in that it ditches all the cruft. I wish they had a consumer-friendly license for it, though. Microsoft's vision for consumer windows 10 is no longer an unobtrusive platform that doesn't get in the way of the user, much less force unwanted features on them.
I definitely remember running windows 2008r2 on my home desktop because at the the time that was all that was available in the "your educational institution neither gives .edu emails or has arranged anything with microsoft" tier of dreamspark.