The EU generally has a de minimis limit of 150 EUR for custom duties but individual members levy sales tax from the first EUR onward. The USA could do the same. Of course, this would make things more expensive, too, but less so than sinking your trade boat through tariffs ;)
If you look at the amount of de minimis goods shipped the year after the amount was raised vs today, they have increased over 10x.
Also the pre 2016 limit was $200, still low enough to allow the temu business model.