By "dummy" do you mean "silly"? "Dummy" as an adjective is not used in that context. Is it silly?
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park sang jooneverything it takes to make a top-rated journalistIt takes [something / someone / an amount of time] (to ...) is an idiom in which 'it' is preposed to take the place of the real subject (the infinitive), so yes, that's a "dummy it".