As someone who has strong opinions on this, and not only has a job but has a job related to exactly sort of thing… We use freebsd.
Specifically to avoid shit like systemd, and other questionable choices forced down people’s throats by idiots who can’t stop touching things that work well because they didn’t invent it.
Servers, and workloads are various- DNS, ntp, databases, a few websites, internal servers running code/apis/etc for internal processes, etc.