There are multiple factors. Cheap shipping from China took advantage of available space in passenger jet cargo holds - those flights have pretty much gone away, so it's now months instead of weeks for shipping time. Second, the USPS has basically been subsidizing China - post is supposed to work on a reciprocal basis. Shipping from China, the shipper pays China Post (which is subsidized by China, and charges squat), who delivers it to USPS, who delivers it free. What little revenue there is goes to China Post. It's supposed to balance and also work in the other direction, except there's not nearly as much stuff shipped the other way. But,
that's going to change, soon. So, right now, shipping stuff from China in a reasonable time (weeks instead of months) is much more expensive than it used to be. And, that's unlikely to change since by the time airlines come back, international postal rate restructuring will be happening. $1 + free shipping stuff from China will be a thing of the past.
