Seems pretty paternalistic to me. Why not let people decide for themselves whether they "actually need" the $5 plastic trinket from china? Do you not trust adults to make informed decisions on what they're buying?
The free rational market has no way to price these in.
Tobacco and alcohol, both of which have objective, measurable negative health outcomes supported by decades of research, versus some vague notion of "junk products" as defined by... who? And this is without even getting into the fact that the tariffs will raise the price of everything, not just these supposed "junk products."
So if the only lever you have to affect consumers is price, then you must factor in the negative factors with higher prices.
i.e. If the price is supposed to be a lever for labor conditions, why just tax China heavily and not Bangladesh?
Why tax more fuel-efficient European cars instead of American-Built Jeep Grand Cherokees?
And if reducing plastic waste is the priority, why would Trump's day include unbanning plastic straws?
Answer: It's not actually about reducing negative externalities, it's about geopolitics, otherwise it wouldn't be so negatively weighted towards a single actor.