How is that not OO then? OO is not defined by Java. The first OO languages and systems were descended from Lisp or built within Lisp, a functional programming language.

OO without inheritance is still OO. OO with immutability is sill OO. Encapsulation is the heart of OO. Polymorphism is also quite important. Inheritance is a distant third property of OO, but it is one common aspect of OO that is highly over-used. Most OO "best practices" gurus discourage rampant use of inheritance these days and say to prefer composition.

Back to the whole point of this thread, Rich Hickey says specifically NOT to use encapsulation (90% of the time). That would then not be OO. No encapsulation, no OO.