The age of the fossil must be determined so it can be compared to other fossil species from the same time period.Understanding the ages of related fossil species helps scientists piece together the evolutionary history of a group of organisms.
Petrie's notions about Egyptology, and archaeology in general, were revolutionary.
His worrying about where a pot came from and what period it dated to and what that meant to the other objects buried with it were light-years away from the ideas represented in this photo dated to 1800, in which "Egyptian pots" was considered enough information for the thinking man.
Petrie was a scientific archaeologist, probably close to our first example.
However, human beings love to see factual precision, and we want to know how old something is.
Please remember that all dating methods, even those termed "absolute," are subject to margins of error. That is a very small amount of possible error range. Modern studies almost always use two or more methods to confirm dating work and to build confidence in the results obtained.