"It's not" only has two matches; the third is "It's noticable". The other two are a whole paragraph dedicated to "it's not X, it's Y" which is a little more than you'd normally expect.
Firefox doesn't seem to discriminate between em-dashes and hyphens using ctrl-F so I'm not sure about those.
Having said that the tone REEKS of AI generation, so meh.
Would AI have spelt "noticeable" correctly?