I can accept the basic argument that the hypothetically "perfect" can want (i.e. lack) nothing.
Does everyone accept this? I'm not convinced of it yet. One could for instance argue that something hypothetically perfect must have NO limits, NO limitations. Having a limit means lacking the capacity to be infinite. The argument that the "best" means there is nothing beyond could therefore be "incorrect". A Christian might say that God is infinite. That He has no limits or limitations. He does not lack anything precisely because he is unlimited ...eh?