In my opinion FBA seller's should have the right see whether their product is delivered or not but Amazon is not providing that for the seller. And my question is, why?
Hello @Seller_QNugBU28BBkPV,
While using FBA, Amazon stores your products and takes care of packing, shipping, and delivering the products to customers' doorsteps. Amazon also handles returns and customer support queries for you. This means you don't have to worry about whether the product was delivered, as any issues will be handled by Amazon, reducing your involvement in these processes as well as visibility.
Regards,
Sakura