It absolutely clarifies the fact that any power not granted to the federal government or the states is the responsibility of the states or the people. The reason it was put into the Amendments was so the federal government couldn't come in years later and implement programs, claiming that since it isn't stipulated to the be the responsibility of the states or the people it was the responsibility of the federal government. It was designed to limit the power of the federal government. You are correct that later court decisions have essentially negated the power of the 10th Amendment, but that is for another discussion.