You are correct to the degree that science begins from observations. However, dismissing one person's contribution to the body of knowledge in isolation ignore

You are correct to the degree that science begins from observations. However, dismissing one person's contribution to the body of knowledge in isolation ignores the vast amount of work in many different times, locations, amounts of detail, techniques used. These interlock to lend incredibly strong support to one main interpretation, that the Earth is billions of years old and has had many different processes work on different parts over all that time. To contradict all of that evidence at once is rather a bit more of a hurdle, and not so easily dismissed.