The ability to join datasets at google through BQ and 'Flink' like pipelines was really un-matched. No matter what dataset you wanted it was accessible and joinable using the same data-lake, query tools, and ACL system. Sure teams differed in how they queried it (tool wise), but GFS made it all readily accessible for joining.

Most large orgs miss this when they make their data lake. Instead making a collection of silo'd data lakes