If you don't think the ERISA is unconstitutional, then point to the relevant wording that you think gives the Federal Government the right to regulate employment agreements between private individuals.
In the American system of government, the constitution isn't interpreted by random individuals voting on how they personally would read the text; it proceeds via caselaw and stare decisis. Since this particular issue was already litigated, ERISA is constitutional; since it was substantially litigated over 70 years ago (I'm not aware of any ERISA-specific controversy that wouldn't also apply to, say, the NLRB or Social Security), it's solidly constitutional.
Among the current Supreme Court, possibly only Thomas thinks otherwise; not even Scalia believes that, say, Social Security is unconstitutional. Of course, if you're a historian you can argue over what a historical court should've ruled, but that's pretty irrelevant to the Constitution as a functioning legal document.
What you describe is not the American system of government, nor the government as instituted by the constitution. The constitution is explicitly written such that every individual, "random" or not, is expected to enforce it. It is not a document that creates a government which is free to "interpret" it as is convenient to said government. The entire point of the revolution, and the extreme set of limitations put forth in the document was to prevent the government from having the power to interpret the document itself.
The constitution does not give the supreme court the power to amend it via ruling or "precedent". The methods for amending the constitution are laid out in the document itself.
Since the document does not give the federal government any power to regulate employment, these laws are unconstitutional. It doesn't matter what the supreme court says, as the supreme court is a group of political appointees beholden to the political establishment.
IF the constitution is not a functioning legal document, then then it has no power. If it is a functioning legal document, then all these unconstitutional laws are actually null and void (as ruled in Maybury v. Madison) and anyone enforcing them is committing a crime.
If it is your position that the existing government is not bound by the limitations of the constitution whenever it decides that it shouldn't be, then the government in question is not a constitutional government, and is, in fact, an occupying force with no legitimate authority. (not that the constitution was anything other than the result of an illegitimate coup in the first place, but for purposes of discussion, I'm granting that the constitution is legitimate.)
Absurdity. The Supreme Court does not amend the Constitution when it rules, it interprets it in order to establish whether legislation is in conflict with it, or which state should prevail in an interstate dispute, and so forth. It most certainly does matter what the Supreme Court says about such matters, because the judicial power of the United States is vested in it and extends to all cases arising under the Constitution.
Your view that the lack of any explicit mention of employment means that any federal laws regulating it are unconstitutional is widespread but self-contradictory. For one thing, employment is a fundamental part of commerce.
I am finding it difficult to believe that I have been downvoted into troll-town for suggesting that legislation enacted by the Federal Government of the United States over the course of the last 62 years might NOT be unconstitutional.
Some of which were contested and deemed constitutional by the Supreme Court (though not the one I mentioned as far as I am aware).
Are people downvoting me because they hold an honest belief that the Federal Government of The United States is an illegitimate illegal entity backed by a corrupt Supreme Court? Just curious.
If you don't think the ERISA is unconstitutional, then point to the relevant wording that you think gives the Federal Government the right to regulate employment agreements between private individuals.