Why is it more convenient to express stress tensor in Material rather than Spatial coordinates?

I was reading chapter introduction about Stress and the author wrote the following about stress tensors:

"Since the current configuration of many problems, especially those involving solids, is not known, it is therefore not convenient to work with stress tensors which are expressed in terms of spatial coordinates. For some cases it is more convenient to work with stress tensors referred to the reference configuration or an intermediate configuration."

Is the material coordinates more useful since its hard to determine the current configuration? If yes,then why is it complicated?