When it comes to describing something that remains after everything else is gone, "is left" is just one way to put it. There are plenty of synonyms that can be used instead, depending on the context of the sentence. For example, "is remaining" or "is leftover" are both common options. Another possibility could be "is remaining behind" or "is still present." When talking about a certain amount that remains, you might choose to say "is left over" or "is left remaining." No matter which synonym you choose, the goal is to clearly communicate the idea that something remains even after everything else has been taken away.