The word “decimate” does not mean to destroy something completely and leaving nothing behind. It actually means to destroy a great or large amount, not the entire amount. Some people tend to use this word in absolute and complete terms, as if there is nothing that can be done, said, or seen after the decimation takes place.
Think of it this way: if a 10-story building gets decimated, then
there should still be a story or two left after the decimation. If
all ten stories get destroyed, then the building has not been
decimated. It has been obliterated.