I can code up SQL easily and find errors. I use sqldeveloper and granted It's not as helpful as say coding Dart on Android Studio IDE in pinpointing where a problem is and making suggestions. But I've been able maintain single sql statements 800 lines long, perform knapsack in a single sql statement, and develop complex packages in Oracle.
If you really want to see super complexity, download and create an Oracle EBS 12.2 virtualbox instance and checkout the PL/SQL packages in the APPS schema and the schemas themselves of which there are over 200.
I've used NoSQL and other SQL databases, each which had their challenges. I like the free tooling that Oracle provides - The APEX app builder and XE database are nice, if not hosted on Oracle Cloud - try the libvirt instance to evade Oracle's cloud grip.
I think the problem here is developer experience and a negative bias toward Oracle, which is understandable and prevalent in the developer community.
Cheers