The tenth amendment obviously did add nothing substantive to the Constitution. The Constitution explicitly enumerates the things the various branches of government can do. Explicitly stating that they can't do other things is no more necessary than an explicit inclusion of "No cheating" in the rules of a game.

The commerce clause thing is a separate issue. Wickard v. Filburn had nothing to do with the tenth amendment, as it is based on a (particularly broad) interpretation of one of those enumerated powers.

I am not a lawyer, this is not legal advice, you should hire a lawyer if you are somehow in a situation where this is directly relevant to you.