Full of bugs, some that destroy speed, some that destroy data, some that just make a feature that you need unusable. More heavyweight than lead (although it gets fast after you throw enough hardware). Lacking any capable or usable management interface (but then, that excludes everyone except for postgres and mysql). Impossible to program. Impossible to predict how your program will run.... And my favorite, absolutely fragile, any wrong code you run there can take everything out of the air.
And yeah, stupidly expensive and comes with the Oracle legal team.
This would've been sufficient, honestly.
Did I say it has bugs?
Anyway the most recent pair I found on the wild was a problem that made indexes of georeferenced data fail at random, pushing your queries into a non-indexed search and breaking things like materialized views, and one that causes some inconsistency on testing clobs for null or empty string (what made them impossible to test for either when it applies). But there's a well known one that breaks optimization plans at random and goes with the last try (it doesn't matter if that it will scan that table 100000 rows 1000 times), and there's some bug where if you create some tables, populate them, drop them and repeat enough times you will lose your database. But that's just from the top of my head.
Oh, of course, that isn't including designed behaviors like the one that takes your database offline if you don't do backups often enough (where "often enough" is something that you can estimate but never be sure about its frequency).
https://www.theregister.com/2021/07/20/how_amazon_broke_free...
Sybase, Ingres
I worked at both a Sybase shop and an Oracle shop. I far preferred Sybase.
Oracle it not that bad anyway, it's just stupidly expensive. I'd choose Postgres any day, but I worked with Oracle a lot and it never was a main culprit in my work. It has its issues, sure, but they're solvable.