Most companies probably realized that they don't have Big Data problems because they only have a limited amount of data which you actually can process in an acceptable amount of time on a single Postgres instance. Distributed data processing has a huge upfront tax and you really only want to be doing it if the data set is enormous.

I guess it is similar to other technologies which most companies or developers would really never need due to their limited scale like distributed databases, NoSQL or microservices: It is interesting technology and engineers would like to get their hands on it because that's what the big boys play with, even if they don't really need it. In the meantime the industry hypes it because the technology is difficult so they know that they can make money doing consulting.

I'm not saying that it is not useful technology, I work at a company where we had the need to go from Postgres to "Big Data" tooling. But for tons of businesses it just doesn't make any sense. And even in our case one of the questions I have most frequently is: What business decision are you taking based on processing this enormous amount of data? Can we not take the same decision based on less data?