Earlier quoted context omitted.
They make a great database?
It's possible it has redeeming features but seems more common to be just legacy. Multiple apps accessing the same DB leading to a gridlock from migration POV. (Plus career oracle DBAs etc in the org). As Oracle is so expensive it skews the architecture decisions towards multiple apps accessing the same DB.
Rumour has it the same holds for some other types of data as well but I lack immediate experience in other areas.
With Oracle you also have a rather robust, exhaustive documentation of error messages and even obscure stuff is likely to be figured out in some forum thread by someone and an indian guy. Postgres isn't exactly bad in this area but you can run into things where you need to go deep in debugging yourself and figure out minutiae of your specific version.
Containers also remove most of the issues with running several instances in development and CI environments.
I still don't recommend anyone to pick Oracle for greenfield stuff, instead you should work around shortcomings in other database engines, but for a large organisation with certain demands that already has buyin it makes sense.