I'm not 100% on "most"... but really most devs I've met prefer the NoSQL options and the devs who did really like RDBMSs seemed to eventually drift into DBA pos

I'm not 100% on "most"... but really most devs I've met prefer the NoSQL options and the devs who did really like RDBMSs seemed to eventually drift into DBA positions. I'm not sure why you focused on Mongo... it is probably the poster child for a bad example of NoSQL. It focused on features and performance while leaving data integrity on the floor. Never understood it's success given its Jepsen reviews. NoSQL excels when it is targeted. Like using Etcd for config management. Consul for discovery. Redis for shared, in-memory data structures. Cassandra for high throughput, write heavy systems. DynamoDB for no-ops, key-value storage. S3 for key-value storage with large storage reqs. Etc.... They don't do as well, like Mongo, when they try to be general purpose. RDBMSs rule the jack-of-all-trade-master-of-none zone.