This falls into a scale up type (vertical) architecture, in what scenarios would you need tin like this? Versus A more scale out/distributed (horizontal) architecture
Let me rephrase rather. a scale out architecture with commodity machines (using Hadoop, kube, mesos etc.) versus an engineered system in hardware. A client purchased a an HP super dome (another highly engineered system) the cost per CPU core, gb ram, tb of storage was horrendous. More than 10x comparable commodity hardware solutions. 8 months later and they hit performance problems, space issues and adding capacity is a serious chunk of change.
What I am trying to understand in what use cases would this make sense?
This is a scale-out solution, it's just higher performance / lower effort than building your own solution from commodity harwdare. Enterprises often want to buy canned, supported solutions rather than expend the R&D to build their own.
What workload does this configuration make sense for? I don't know, especially with those ARM cores. My guess would be the cluster performs well on workloads similar to Apache Spark. But I don't know why you would choose one over the other.