Surprising because one of the driving forces behind accelerating adoption of on-demand IaaS and various PaaS like Serverless is that too many expensive server resources lay idle. According to James Hamilton, chief Data Center architect at AWS, server utilisation remains very low (10%–15%) despite servers being the most dominant cost of building and running a data center (which is to say, folks pay through their nose for servers yet those are under-utilized by a huge margin) [0]
Edit: sentence fixing
There was a period when it wasn't clear that you didn't need both resource management and container orchestration. One of my colleagues was quite convinced at the time that we needed both Mesos and Kubernetes. If course, the market coalesced around Kubernetes which largely backfilled the missing capabilities.