Because the customer didn’t pay the tariff, the business did - unless of course the business flat out added a “tariff surcharge” or something of the like to the total that the customer can see.

Increasing the cost of an item by the amount of the tariff is not the same as making the customer directly pay the tariff. The business was charged the tariff. They were invoiced and they paid it. The customer didn’t. The customer just bought an item at shelf price.