To be precise, the 10th amendment is a nullity if you already accept that the federal government is one of enumerated powers. At the time of the founding, that was a novel concept and it probably made some people feel better to have it stated explicitly. But today that's taken as a given. The debate is never over if the government has powers not enumerated, but whether a particular action falls within the scope of an enumerated power. And the 10th amendment tells you nothing about the scope of the enumerated powers.
To be precise, the 10th amendment is a nullity if you already accept that the federal government is one of enumerated powers. At the time of the founding, that was a novel concept and it probably made some people feel better to have it stated explicitly. But today that's taken as a given. The debate is never over if the government has powers not enumerated, but whether a particular action falls within the scope of an enumerated power. And the 10th amendment tells you nothing about the scope of the enumerated powers.