The people receiving stuff from Amazon were supposed to report and pay the sales tax.

If you or I aided and abetted widespread tax evasion, we would get our asses handed to us in court.

If you had said "were" instead of "are" this would be a true statement. Since South Dakota v. Wayfair in 2018, states have been allowed to charge sales taxes on businesses that have no operations in their state. That decision overturned 1992's Quill v. North Dakota, which held as you say. But that is no longer the law of the land.

The 5-4 majority in 2018 included two justices who were part of the unanimous holding in 1992 (Anthony Kennedy and Clarence Thomas), voting to overturn their own decision from a quarter century before.