AFAIK there are lots of items that sell in Walmart that could be bought without directly examining them in store, if good enough online info were provided to compare and contrast them to other items of a similar type. Also, lots of those items are made in China anyway and probably are available there cheaper than anywhere else.
So, why don’t we see an Amazon-meets-Walmart operation in China that would allow customers to assemble a big shopping cart of such items, put them together in a big box in a fulfillment center over there (cheap labor, no expensive American execs, convenience of a huge fulfillment center with more merchandise stocked than any particular Walmart) and then ship it by slow, cheap sea transportation to the customer - initially to the Pacific port cities (Singapore, Tokyo, San Francisco, Seattle and so on) and subsequently further inland by truck, if the idea catches on. If last mile delivery by local mail proves too expensive because of mails tendency to waste money on unionized employees, they could deliver by their own truck to distribution centers, which could be basically a storefront similar to UPS store, where the customer would pick up by himself by car.
So why don’t we see something like that in all its glory already? There are certainly some dropshipping operations from China out there, but they don’t qualify even as a parody on actual Amazon, let alone a true Walmart equivalent.