You can get to VP without competence. Staying there requires it. You don't necessarily have to be the most competent person possible but there is a floor.
So from what I've seen and learned, there's definitely a difference between being truly smart/visionary/creative etc vs just being "not dumb". And while I suppose the latter could also be deemed a kind of competence, I think what the others are driving at boils down to this - people with connections or just a knack for politics and schmoozing can get pretty far ahead and many underlings often mistake their rise for some sort of amazing technical or creative ability.
I don't know if I agree with that. Anyway, competence comes at various levels.