

This is the system working as designed. I’m not sure how anyone missed that.
And while tariffs were in place Amazon was passing on those savings, or lack thereof, to customers. So they mostly didn’t see any losses from paying the tariffs. Then they get refunded, and then it’s less that the government actually paid Amazon anything, they just gave them a reason to charge people extra in shipping, for no good reason.
Whether those costs were rendered in the shipping cost on Amazon, or by simply marking up the prices so that they could account for those extra costs, doesn’t really matter.
Consumers ended up paying this bill. The 650M “refund” was just the government exempting them from costs that the government should not have collected from them in the first place.

They never do.