Yeah, that's a really good overview. I think it's interesting how progress in the DevOps field is characterized by removing things more than adding them, and I think it's great. In a way I think that's the highest and hardest aim of computing technology, not deciding what to build, but deciding what to leave out.
FreeBSD may have less then 1% of server market share but FreeBSD drives a large amount of network traffic. For example FreeBSD runs the open connect CDN that Netflix uses and that accounts for almost 32% of North American downstream traffic [1]. Limelights edge CDN nodes run FreeBSD and Limelight is one of the Bigger CDN companies out there [2]. Juniper routers are FreeBSD based and are the second most used routers after Cisco. There's plenty of other examples but FreeBSD may not be widely deployed but it serves a significant amount of the worlds internet traffic.
The Modern Operating System In 2018
https://www.youtube.com/watch?v=dR2FH8z7L04