The issue for the importer is cash flow. The tarifs have to be paid on entry, ie before the coffee is sold.

This suits large importers over small ones, they have the cash reserves to cope.

The other issue for importers is uncertainty. The tarifs might be high this week (when my stock arrives) but it might be low next week when my competitors stock arrives, putting me at a disadvantage.

So "shelves being bare" is primarily a business risk / cash flow issue. Partly handled with more frequent, smaller, orders (driving up consumer prices some more.)

And yes, I agree, most American consumers don't understand that fundamentally the goal of tarifs (good and bad) is to drive up the price. To that end though the administration is being very successful.