That wouldn’t be true either because of the Turing-completeness point e.g. the Plum package for Python, but yes, it’s much better to claim that multiple dispatch has some power or expressiveness that OOP does not. It’s true the other way too, but obviously we’re here because we think one side has a larger native advantage.
I would still argue that it’s not an an argument for OOP, as it’s the capacity of python as a language that allowed plum and not OOP specifically.
Where as for MD, his strict capability + tracking of method owned by an object is enough.
(in fact, you can even store methods in the object or use functors, whethever)