My impression is that the Wolfram language is not particularly object-oriented and that it does not support OOP. Am I wrong? It has certain features that are enablers for libraries supporting OOP.
Not sure either. Could exist but don't know about it and sadly Wolfram lacks a formal specification. After bit of searching though found there're few[0] packages to enable object-oriented programming. So can probably assume there isn't native support for it. Seems the Wikipedia page needs more thorough research.
OTOH Java has a defined language standard (independent of implementations), which describes classes/fields/methods/dynamic dispatch/inheritance/hiding/constructors, ... ( https://docs.oracle.com/javase/specs/jls/se22/html/jls-8.htm... ).
I fail to find a similar language definition of OOP for Wolfram. That could be me.