Simply put, you can't be sure what you will spell next, so you have to keep spelling it out with pieces. However, there is not only one kind of debris to refresh, but several series of archaeological sites are refreshed at the same time on a continent.
For example, I want to spell a doll ornament of Tyrande of the Night Elf Archaeology Department. I dug a small version directly to make it up. There were countless garbage periods before.
So: Archaeology destroys life.