Kershaw wasn't and still isn't this purely talented. He does not throw 100 MPH, he does have an awesome curveball, but was not ever in consideration for #1 overall that I remember.
Yeah, Giolito would have to work really hard to be as good a pitcher as Kershaw, but he is more gifted than Kershaw.
Taylor was drafted at 19, and I don't think he had this kind of talent. Giolito is already 3 inches taller at 17 than Taylor was full grown.