What is the Windows Server OS missing?
If Windows Server was free, what is it missing as compared to Arch, Red Hat, or Debian Linux that would keep you from using it?
Linux has been the go-to OS for servers for so long, it supports every scenario from simple home labs to high performance webservers, complex multi node service orchestration, globally distributed data stores, you name it.
Also, I don't know how to do simple stuff in Windows land such as using Powershell or how to harden a sever instance. Like I don't even know how permissions, users and processes work in Windows.
Given the effort involved in learning a new OS and the risk of using something proprietary (from Microsoft, a company that has acted in bad faith consistently over the years), it would take a HUGE upside in something like performance, ease of use, etc... for me to make this movement.
What does Windows Server offer that is better than a Linux server?
I can download and install a variety of Linux servers now. There are tons of free software that I can install and use or modify for any task I can think of.
I can't think of any reason to use a Windows Server, free or otherwise.
More sane minimal OS would be nice as Core and Nano didnt deliver. Nano was a good effort but they stripped it down way too much. Give us kernel only with pwsh and winget and its all good.