I believe the states would say that the Feds interfering in their business of collecting sales taxes for things sold to their citizens was indeed, that very thing... LOL...
The only reason why a majority of the states have “held off” during this time is for the promise of a all-encompassing and smooth system being put into place where they wouldn’t have to have a “mish-mash” of competing state regulations, fighting against one another. They’ll hold off for the promise of that one to come...
Maybe the reason you’re making a series of non sequitur replies is that you haven’t actually read the Constitution, or at the least, you haven’t read Art I Sec 9 & Sec 10.
Or maybe you think State law trumps the Constitution’s State restrictions.