You clearly have never dealt with an Elasticsearch cluster that has entered the “red” state. It’s not just about cost, it is about not having to wrangle and lasso a big cluster.
My take on it is that for some companies using hosted Elastic (not AWS’ horror) is more probable if their business is not maintaining large clusters in house. This is along the lines of having a live-in nanny more than an occasional housekeeper. It is a luxury, and one in which having an Elastic nanny (PaaS/DBaaS) might make business sense.