Exactly correct. I’ve got a post in the works called “Elegy for Hadoop” that traces the history back to the early 2000s and arrives at the present day where you can easily get on-demand instances with 500Gb of RAM and use it for only your application’s lifetime. If you want 1000Gb instead of 500gb it does not cost 5x it costs 2x, significantly invalidating the “need to use excess commodity hardware” premise of the distributed map reduce architecture.

Edit: I don’t mean to suggest that there is no reason to use Spark, but ~95% of the usage in industry is unnecessary now and should be avoided.