This is true in some other countries where a high court (sometimes called a constitutional court) is often tasked with deciding the legitimacy of a law, the all

This is true in some other countries where a high court (sometimes called a constitutional court) is often tasked with deciding the legitimacy of a law, the allowable scope of its application, etc, outside the context of a particularized, concrete dispute involving claims of actual or imminent harm or loss. (Often the context is settling a speculative dispute of authority between government branches.) Sometimes that might be the highest court's only job. That is definitely not how the United States Supreme Court operates, though some US state supreme courts will hear and issue opinions on purely abstract legal questions, especially if submitted by the legislature or some other office given special privileges.