Yes. I think the major advantage of NoSQL databases was easy horizontal scaling (shard + scale + seamless failover) at a time when it was difficult to do these

Yes. I think the major advantage of NoSQL databases was easy horizontal scaling (shard + scale + seamless failover) at a time when it was difficult to do these things with SQL databases. However, NoSQL's original advantages have started to fade with db's like Citus and TimescaleDB, and even FB's MyRocks. NoSQL databases are optimized for straight data retrieval and horizontal scaling. If you want to dump lots of naturally unstructured or semi- or variable-structured data (like logs) into a distributed data store and retrieve them quickly without doing any non-trivial manipulation on them, Mongo will likely fit the use case. It's fast, strongly consistent, supports secondary indices etc. However, as soon as you need to manipulate your data (i.e. analytics use cases), you're much better off doing a bit of data modeling up front and using a SQL database.