Initially, stores tried to manage demand by blocking tax-free purchases, hoping to discourage tourists, mainly from China, from buying cards.
For many, it still makes financial sense to fly to Japan, pick up a 5090, and either resell it or use it for.
Chinese board partners have long been suspected of selling GPUs directly to cryptocurrency miners, bypassing the consumer market entirely. Now, with the AI boom, these companies are shifting even more stock to AI server manufacturers, who are willing to pay a premium. That leaves even fewer GPUs available for regular gamers, making GPU-buying tourism a surprisingly viable option.
It does kind of illustrate how hard it is to restrict the flow of goods.