Microservice achitecture promotes splitting data cross multiple databases making it impossible to do proper DB JOINs from application code.

Then companies buy a solution to aggregate all the different databases in a single "data-lake" (or whatever buzzword is hot right now) so you can do OLAP queries. Without consistency guarantees of course.

And I am not saying this is never the _right_ solution, but it should almost never be the _first_ solution